DescentBB

D1 10-level version of Apocalyptic Factor (it's on DMDB). Level 2 won't load; freezes game in Dos immediately every single time.

Checked all ten levels and the others all load.

Looking into D1 version to begin with because based on Level 1, it seemed more reasonable for single player than the original version. It was actually fairly relaxing difficulty in the D1 version despite tons of bots.

Try using Rebirth instead of DOS version. It has better graphics anyway, and some bugs fixed (from what I remember - homing missiles turn rate + mouse sensitivity bug that in my case rendered the game unplayable with the mouse). If it still does not work, you can report the bug to Rebirth developers, at least. Anyway IMO difficulty of AF (I mean full D2 version) is overestimated, just look for correct path through the levels and save a lot, plus it will get significantly easier (at least for me) starting from L4 (apart from level size, of course). I did it on insane 2 times, and cannot say that I spent too much time reloading games in the second run, except for some bosses. At my first walkthrough it was hard because I did not knew where to go.

BTW there are many campaigns that are much less playable on Insane, than AF, those include commonly played ones, like Konflikt at Karon, Entropy Experiment, DieHard, Phobos Encounter. I even remember one campaign which had robot with mercury missiles and homing missiles, that moved faster than said mercury missiles on Insane! Obviously no one even tested it.

It does work in Rebirth but I like my Descent as classic as possible. Enemies drop things too often in Rebirth despite the RNG code apparently being the same.

All the campaigns you talked about except Entropy have new robots, so it must be an issue if those aren't tested for Insane. Probably TEW is like that too if I was to guess. I've played Phobos Encounter on Hotshot with no problem. What was broken on Insane in Phobos and Entropy (since Entropy doesn't even have new robots)?

I will mention I cold start all levels, or at least like to. I wonder if you can do AF cold start. Level 12's start I'm dreading. A lot.

Rebirth might have more advanced graphics technology Alex, but that's not the same as better graphics.
Robot explosions look awful and they're not nearly as visually satisfying as they are in either DOS or the other source port -- and the satisfaction of finishing that fight and getting that boom is still a big part of this game's experience in solo, dated graphics or not. The advanced visual options, far from alleviating that problem, only draw more attention to it and compound that by somehow making the game's environments look more dated instead of less.

Rebirth is visually all over the place now and can't seem to decide whether it wants to be a graphical update or "pure" Descent. It still runs beautifully in the multiplayer department, but for singleplayer, Rebirth four or five years ago was way better than it is now. Some of us would rather stick to DOS when we want our Descent "pure".

kakhome1 wrote:It does work in Rebirth but I like my Descent as classic as possible. Enemies drop things too often in Rebirth despite the RNG code apparently being the same.

All the campaigns you talked about except Entropy have new robots, so it must be an issue if those aren't tested for Insane. Probably TEW is like that too if I was to guess. I've played Phobos Encounter on Hotshot with no problem. What was broken on Insane in Phobos and Entropy (since Entropy doesn't even have new robots)?

I will mention I cold start all levels, or at least like to. I wonder if you can do AF cold start. Level 12's start I'm dreading. A lot.

Holy hell, no idea you agreed with me on Rebirth's graphical problems. The robot explosions look like one big misunderstanding, and missile impact sprites have been given angles, which makes them get cut off by surfaces they impact against, which also looks like crap. The software renderer build of Rebirth fixes this somehow, but not entirely. Still, it's probably best to just set up your DosBox and enjoy the DOS version with a single click if you want the best looks coupled with some nice, nostalgia-fueling pixellation.

I just wonder how I should play (non-XL) levels that Dos can't take, such as AF D1 Level 2, Nefarious Assault, or even ones which slow it to a crawl, like TEW Level 9, 26 (possibly among others), or a handful of Vignettes map? Both are increasingly common from the late 2000's onward.

Honing flash missile effects are also extremely strong and long lasting in Dos, for instance try starting Level 4 or 14 of Obsidian cold (Hotshot). Can't think of any reasonable strategy there except to make a mad dash away from such robots at the start.

Also in AF D1, packs of robots dropped by killing a robot often start out not being particularly mobile, especially the green lifters, which sometimes are stuck together in a 'cluster' and can barely move unto at least one has been destroyed.

In terms of gameplay functionality, is Rebirth still acceptable?

1. By better graphics in Rebirth I meant better appearance, i.e higher resolution, smoother textures (with appropriate settings), things like this. Sorry if I said it in the wrong way.
2. About DOS version vs Rebirth - are you guys serious that DOS version can be better in something? With it's 640x480 mode, square pixels, lack of smoothing, control bugs (it was simply impossible to use mouse in my case)? IMO Rebirth lacks nothing in gameplay compared to the original (for me it was identical except better visuals and fixed bugs), I did not found any difference in explosions too, about flash missile effect I don't care. But on insane it disorients your for enough time to be killed. Of course there are retro-fans that buy old PC's and install games under genuine DOS, that I can understand, but it is another matter.
3. I replayed both Phobos and Entropy on insane (otherwise I couldn't tell what was wrong with them, because I forgot them). What I see. Phobos is mostly shooting gallery (most robots can be killed from out of range if you don't rush) and very easy if you have enough gauss ammo on L3. However coldstarting L3 and especially L4 would be major PITA (I did it with L3, hardest part is to get to energy center without completely running out of energy). Then it becomes easy. Coldstart L4 - good luck, I don't want to try it. Bosses are trivial (last one even does not shoot at you...). Geometry is very symmetric and I won't say it is inspired, but it is ok. But very bleak compared to, say, Obsidian. So i was mistaken a bit about Phobos, it was unbalanced another way (too easy instead of too hard).
Entropy - very poorly balanced robots (i would say they are new robots because they have modified weapons). In fact it is nearly impossible to hit them with your starting weapons, so I ran out of energy many times before reaching the energy center. Still grinded through the 1-st level (again it becomes a shooting gallery after you reach the energy center). Probably if you had more adequate weapons (plasma cannon, maybe gauss, or at least vulcan with enough ammo) it would be ok. Level geometry is fine, resembles Obsidian a bit. 2-nd level - abandoned it, trying to hit anything there with laser is too frustrating, I simply lost patience and quit it. Anyway both Phobos and Entropy are very small and so it would be hard to compare them with larger missions that I mentioned.
4. I did not cold started anything in AF. It was hard enough without it. I cold-started some of stock campaign D1, D2 levels (most difficult ones), but did not found that it changes much for me. Most of the time the cold start was different from non cold start only in small starting part, which does not make a big difference (like D1 level 19, D2 L16). There are other cases of course (for example D1 L9, L11, D2 L21). In general I am not a fan of cold starts, imho difficulty level matters more than cold start vs normal start. Also sometimes cold start creates problems with reaching energy center which I hate.
5. TEW - I did not found it's robots that difficult, because of careful placement and introducing them at right time when you had the weapons to deal with them. Of course Golem and Warlord are frightening but not a big problem when you know how to deal with them and where they are.

1&2. I just prefer to have my Descent served as classic and vanilla as possible with the fewest number of deviations from the original experience or at least the experience the author of the mod intended when it was built.

3A. I don't know how well tested they were on Insane, but Phobos Encounter and Entropy Experiment are both classics and so are their respective sequels (Project: Mandrill and Entropy 2: Vengeance). At least from all reviews that have been archived, they were almost universally regarded as 'cream of the crop' at the time and better than Orion Nebula Project (which you mentioned as a mission you do enjoy more). How likely is it that there are similar issues on other difficulty levels with these missions?

3B. Obsidian has a lot of symmetric geometry as well. Not all the levels, but many of them. Phobos also has no more symmetry, overall, compared to Entropy.

3C. As for 'shooting galleries' (i.e. I'm assuming you specifically mean enemies out of range?), almost every Descent mission or level, including the official ones, have them sometimes, or at least points in which there are ways you can easily get out of range to fire at an enemy safely.

3D. I generally don't even use D2 primary weapons unless I absolutely must (with the except of Omega to get rid of those super annoying Guppy bots) as I feel they are overpowered (Gauss may be most of all) and most of the time, levels are perfectly possible without them (on Hotshot).

4. If I can't reach the energy center fast enough and run out of matter weapons, there's always at least two lives to sacrifice when cold starting. One cold starting problem that can show up in D2 and there is no way to get around is secret levels that have access from multiple different levels. If you cold start, the game will always think you haven't been to the secret level yet. I don't think source ports even fix this. However, Vertigo and *most* custom missions (Obsidian and Lost Levels are definitely among the exceptions) don't have multiple teleporters to the same secret level, and it doesn't affect the regular progression regardless.

5. I'm only through Level 3 of TEW and only playing Hotshot. I just know when TEW was first released, there were lots of 'rants' about how brutal it was, and while Hotshot and (even more so) Rookie were later nerfed, Insane wasn't.

You have a software rendered build Xfing? I've been trying to get my paws on that for an eon and half and for some reason anyone who says they can help me suddenly disappears.
...you aren't going to disappear are you?

Alex, if you haven't seen a difference in robot explosions you're either using a software rendered build yourself or you haven't looked too hard. Rebirth (because of some hardcoded OpenGL attribute) renders the explosion behind the robot and at most angles makes it look like something exploded behind the robot and then the robot just vanished. DOS renders the explosion in front of the bot so it looks like the bot is actually the thing exploding.
From what I can tell your satisfaction from the game comes tips the cerebral end of the scale; I know mine is equally cerebral and visceral. I wouldn't be surprised if the appearance of explosions is far more important to me than it is to you.

As for resolution and texture filtering... well, turning up the screen resolution doesn't change the texture resolution and turning on texture filtering draws extra attention to how pixellated the textures themselves are. Antialiasing (which works on geometry instead of textures) would be a cool feature to have but as far as I know it's not in the plans or likely to ever be.

It seems that I did not noticed about explosions appearing from behind in Rebirth. True, I just switch my attention to everything else when the robot explodes,or even hide behind the corner to avoid being hit by return fire, so "not looking too hard", exactly. I use high resolution with Texture filtering = anisotropic, to me it looks nice. But I checked the original texture rendering, it has some charm too. Anyway higher res makes robots and projectiles look better and easier to see from long range.

@AlexanderBorisov Any thoughts or comments on the points I made in a list a few posts above?

To kakhome1
1&2. Same for me, I just did not noticed those minor differences between rebirth and DOS, however was impressed by rebirth advantages. But I still don't accept DX-XL, because it alters the gameplay seriously in default mode, as far as I remember it has some "nostalgia" or "classic" options, but even with this, its improved visuals are too distractive for me. Not saying they are not good, maybe if you play at lower difficulty just for fun it will work.

3A. I did not played Mandrill; played Entropy2, but forgotten most of it; it was very strange to say at least. Plus it is all grey and not memorable. To me Orion Nebula had much better geometry and especially texturing, but a lot of balance and "reach the energy center" issues, I played D2 version of Orion Nebula, hope D1 is better. I would not say it is so much due to difficult robots, but on Insane they are too evasive, you just can't hit anything and run out of energy. Sacrificing a life does not help either, because you cannot beat those small fast robots with lasers effectively. In short : cold-starting anything in Orion Nebula D2 version on Insane would be next to impossible. And even in normal play if you have no vulcan ammo at the beginning of the level, your chances of reaching energy center on Insane are very slim on Insane. About other difficulties, I did not tested, but I think if you can hit class 2 drone or or baby spider with laser at some difficulty (not with 1 of 10 shots), it becomes ok.

3B. I am not a fan of symmetry in general, even in Obsidian my favorite levels are Icicle cluster which are not symmetric.

3C. Yes, especially in Vertigo, TEW too (level 26 for example), in AF, but not to the point where you can destroy 95% of robots this way.

3D. On Ace and Insane difficulties with no death no-save limitation, there are no overpowered weapons. Especially when you cold-start.

4. I play no-death. If I am dead - I restart the level! Otherwise it is like using two saves per level. To me mastering one well designed and challenging level to the point I can beat it reliably is more interesting than playing on easy mode or save scumming through the new campaign. Edit : of course if I start new campaign I use saves (and sometimes even cheats) for initial learning of the levels.

5. Don't believe in the brutality of TEW, it has clean difficulty progression, and well tested on all difficulties, so ways to deal with difficult situation even on Insane difficulty are always given to the player, with very few exceptions across all campaign. I did all levels W/O saves (including boss levels), no save no death but without cold start, except L25 where cleaning boss room and killing boss itself seems too luck-dependent, possible maybe one of 20-30 times, the level itself was very hard too (I was not even cold-starting), probably the same success rate (1 of 20-30 to get to the boss). So theoretically it is doable too, but I did not want to waste time on it.

Alter-Fox wrote:Rebirth (because of some hardcoded OpenGL attribute) renders the explosion behind the robot and at most angles makes it look like something exploded behind the robot and then the robot just vanished. DOS renders the explosion in front of the bot so it looks like the bot is actually the thing exploding.

It's probably centered on the robot, but because that means half of the robot is nearer to you than the explosion sprite, it's going to look almost the same as if the explosion sprite were actually behind it. I think the original software renderer just drew the explosion/effect sprites last and ignored intersections, which meant they'd obscure anything they overlapped with - but for explosion effects that does look better than making you painfully aware they're just floating polygons.

I wonder if this Rebirth software renderer mode also uses the legacy method for drawing polymodels. That would make things... interesting.

@AlexanderBorisov Thanks for the response. Some items I don't have to add on so I didn't include them:

1&2. Do you ever play XL missions, which of course require XL? I don't mind it for missions that are specific to it.

3A. Insane, alone, is a lot different from Hotshot, and no death no save is a big thing as well.

3C. That said, the 'shooting gallery' issue is a fundamental design flaw that would spread across all difficulty levels. I'm pretty shocked that it's there in missions so classic and well known. Besides Phobos and the first Entropy, do you recall any mission (including official ones) that have this problem to this extent? I bet it's just what happens when you have too many expansively big rooms especially when they are connected to lots of side areas.

3D. I would agree especially when no save no death you want strong weapons. Still I like playing in a way where I vary my weapons more.

1. No unfortunately I didn't. But if someone knows XL missions worth playing (meaning - very different or better experience in some aspect than non XL missions), I can try. For now I don't have new interesting Descent missions to play under my conditions.
3C. Yes, I consider it a design flaw regarding robot choice and placement. Because you can have robots in big rooms and still have a lot of challenge and fun. For example in Obsidian, AF, of course you can kill many robots from afar, but you must be careful, approach from the correct side to do it, also often robots close distance fast enough to engage you. Definitely NOT shooting gallery if those are homing missile robots, or flash homing missile robots. Consider TEW level 26, another TEW level with Mantids in the room with huge pillars, TEW level 23 (the one with huge interconnected area), they are among my favorites.
I don't remember other campaigns suffering as badly from this, if some campaign had serious flaws I tend to take a quick look then forget it. So need to replay such missions to tell what is wrong with them.

There is also another frequently occuring flaw in many missions, for example Project HYDRO - you are immediately confronted with strong robots at close quarters without chance to maneuver. For example how are you supposed to fight 2 sidearms on both side of entrance in project HYDRO, on Insane? Same in Saturn, starting from L2. It seems that good robot placement and balance is very difficult issue, needs a lot of testing and understanding how robots behave on various difficulties (incl insane of course).

3D) Ok, But for example, Obsidian forces you to use many weapons even w/o special limitations and cold start on high difficulty. I used phoenix a lot there, to hit campers around the corners, used smart mines (and of course smart and guided missiles) against those homing flash missile robots, omega to hit through grates, plasma when I was out of gauss ammo (on Icicle levels), helix against most bosses,and I cannot say I had a huge stock of weapons in the end! And no way it was a gauss-only battle. I think that no save no death high difficulty makes the game much more strategical and requires a lot more thinking to complete a level and also careful weapon choice. Just good reaction and shooting accuracy won't do in most cases. Of course, you should be able to dodge homing missiles, and stuff like this, but in first place you need to minimize number of missiles shot at you.

@AlexanderBorisov

1. Worth trying though I haven't finished them: Anthology, Dimensional Intersect, Black Prophecy XL, and The Sphere. Also I know this isn't an XL mission but if you like themed level clusters you need to try The Lost Levels, if you haven't already. You can remove new weapons if you desire.

3. Not much to add but can you cold start Level 14 of Obsidian? I have to just fly away from the first room even on Hotshot. There is a homing flash missile enemy on both sides and no weapons or upgrades I can find. There's an invulnerability but it's blocked by a grate. If you can't cold start it, how do you handle the opening of this particular level non-cold start (but on Insane)?

You can deal with initial room like this:
https://www.sendspace.com/filegroup/93L ... 4yNhpNXIWg
but it requires some luck, and you are still sure to run out of energy later... I don't think Obsidian is intended for cold-start, in fact you are nearly always short on ammo after level 7 if you do normal run. However in normal run (can't record because I don't have saves) I'd shoot one guy out of range with laser like I did here, then use gauss to finish it, the second - i'd try to repeat or just jump out and use gauss+mercury then dodge it's flash missiles with afterburner.
Alternatively use guided or homing or smart missiles for one guy. Also this L14 is only level in Obsidian that I was not able to beat w/o saves, had to save before the boss (you will see why if you reach it). Cold-starting everything is not the best idea, some levels are obviously not intended for it.

@AlexanderBorisov

That's a really impressive job starting out even if you do run out of energy. I can't seem to keep them out of firing range (even on Hotshot!). But those homing flash missile enemies look to be a pretty common type in Obsidian. Sadly, I hate HATE H--A--T--E homing flash missiles, I think they are extremely overpowered and should be reserved for bosses only, or should be capped at 90% blinding per hit. However, in cases where you don't have Gauss ammo and aren't able to fire outside of range, how do you generally deal with these robots? I'm definitely looking for whatever you find to be the easiest way possible when lacking Gauss or ability to fire from afar.

Well I try to reduce the risks as usual. Use missiles (smart, guided) if you have any; smart mines if its behind the door (put mine at the door, open the door from afar, shoot mine, robot dies from smart globules). Phoenix if you can. Flash missile from the corner and then shoot it while it is desoriented.
Learn to dodge homing missiles (works in open space only, not always practical because other robots will shoot you when you are dodging). With afterburner it is much easier. But possible even without. Use Vulcan as substitute for Gauss, or plasma (but not lasers as the tend to push the robot back and have less stun effect). But in fact most flash missile robots in Obsidian can be handled without direct encounter at close range. Same for Vertigo. Also there is a trick - if you hit ESC while flashed you can see the screen non flashed while paused. Although I don't use it, kind of cheating.

Seems to be the most common solution I'm seeing (lacking powerful primaries or secondaries) is to snipe, which looks on its face to be reasonable (and logical). However, these particular robots (the same ones at the start of Level 14) seem to be particularly hard for me not to be seen by, and when they fire, it seems like it's an almost guaranteed hit given how fast these flash missiles are. (I'm playing in Dos, no Afterburner this early in the levels either.) What vantage point are you usually best at avoiding being spotted from? Also, even Vulcan can push them around a fair bit.

You can start firing when you see tiny part of the robot around the corner. If you are lucky, it will not return fire (because it does not see you) or its missile will hit the corner. Also, as first shots connect, robot is stunned and does not fire back. But only if you hit with every shot. If you use vulcan you can even move out of the corner while continue firing. So your point would be 1) as far from the robot as possible 2) you see smallest part of the robot possible. BTW some robots have larger hitboxes than its visual appearance, so you can hit them without even seeing!
This is called corner sniping, of course it is a kind of dirty trick so I try to avoid it when possible. So if I had dilemma - corner snipe everything from cold start of fight normally on normal start I would choose the latter option. Anyway, it is useful to first learn the level well without limitations like cold start, learn to deal with enemies, perfect your flying skills, than try cold starts.

The biggest thing I like about cold start is to always begin a level with no score and only two lives. If I accumulate too many lives it is too easy. If I go entirely no death it's often too hard. I also am not a fan of playing the same level twice unless it is far apart.

How critical do you consider D2 primaries to be in Obsidian compared to playing with only D1 primaries (excluding bosses)?

As for the flash missile robots my shots always seem to push them around. If I don't reposition exactly right every time, or even if I am not fast enough, they'll get me. How can I strategize so they don't get pushed as much?

Well you learn by repeating the same many times, any way. If no death is too hard, consider fixed number of saves per level or saving after each key, then reduce #of saves. Thats how I did it. If you learnt the parts of the level well, try to execute it in one run.
For Obsidian I'd say, playing it with D1 primaries only is not fun. On higher difficulties Gauss is essential. Plasma cannon can replace it in many cases, as it does not push robots so much as lasers, and robots don't dodge it as much. Vulcan can be partial substitute for gauss, but in Obsidian you will quickly run out of ammo even in non-cold-starts (because Vulcan consumes more ammo).
About corner sniping, you have to move constantly, to keep a small part of robot visible, otherwise you will lose it or it will shoot you. Requires practice and some luck, yes.

Usually even infinite save no death is tougher than I want. That's why I prefer limited deaths with (limited) saving only on my last life or in extremely hard areas.

If playing continuous, I build too many lives up. I want my lives to always be what they'd be if I cold started.

In Obsidian, what robots do you think Gauss, even on Hotshot, is not overpowered against and will actually consume some of my ammo? My normal problem with Gauss is there's usually more ammo around than I could ever use. Definitely that way in Counterstrike.

Don't quite get it, continuous run wont give you more than 2 lives per level on average. So you won't build many lives if you are dying in each level.
Obsidian, starting from L7 you can easily run out of gauss ammo (but you have plenty before level 7). I'd use gauss for anything I cant hit with laser or plasma (this means very small fast bots), or for smth that need to die quickly (like flash missile bots or DRP or smart missile bots). Also gauss bots. But I would not care about overpowered weapons until I can do a level without saves and deaths. For me, it's simple math : how to use all available weapons to maximize my success rate over the level. Yes, in CS and original campaign, you have enough ammo, so nearly all levels can be cold-started without major pain in the ass. I see it as good design. But some require good knowledge of level's secret areas.

@AlexanderBorisov

1. I could play and see but many levels I don't die that much on. So they could start accumulating and I would lose track.

2. What is DRP?

3. Since I like to play levels only once, I prefer being able to best therm under the same standards and assumptions I use for the original D2 levels. In most levels it would be vey easy on Hotshot to just about use nothing but Gauss start to finish, except for reactors. I want the #2 weapon to be one I have to actually be strategic about when I use, as opposed to basically staying on it the whole level or majority with no worries.

1. Just try and see how many you will accumulate in Obsidian without saving everywhere.
2. DRP is Obsidian robot that fires mercury missiles (like Seeker). http://descent2.com/obsidian/robots/robot17.htm
3. Does not make sense to play everything under the same conditions. If you confront new robots you often need new weapons, thats logical.
Also, depends on the definition of "easy". With unlimited saves you can beat nearly everything with red laser. On Hotshot enemies are very slow, projectiles are slow so I often run into them after dodging, you can run past all robots directly to the exit, I remember one guy did all D2 Counterstrike in less than 40 min on Hotshot (speedrun). In D1 also most levels can be speedrun on Hotshot in less than 2 minutes. Even if you wanna beat the robots, I think you can do it with lasers only on Hotshot, except maybe ones with homing missiles. So if you want challenge, strategic planning - first raise difficulty, then use less saves (or no saves). In short, Gauss is best primary of D2, but Obsidian is intended to be played with it, as you can have it in first level (through the secret level) and officially in L2.

Same as Vertigo, which is mainly what loses it points in my mind.
DRP! My old friend DRP! I love DRP! Or as I call him, Lord Staphylococcus. Don't ask.

Alter-Fox wrote:You have a software rendered build Xfing? I've been trying to get my paws on that for an eon and half and for some reason anyone who says they can help me suddenly disappears.
...you aren't going to disappear are you?

I simply asked nicely for one on the Rebirth boards and got directed to the download. I played around with it for a while and deleted it anyway, since it's not much better than the OpenGL build after all. You could ask Zico and he'll tell you where to download one if you're so inclined.

AlexanderBorisov wrote:I don't think Obsidian is intended for cold-start, ...

Correct. I recall trying some of the later levels cold-start during development, found they were kind of brutal, and my reaction was "oh well, you're not going to be starting from scratch anyway". It was play-tested, but we generally did that by playing it all the way through. Still whiffed on the level 14 boss though; it's too unforgiving when players make mistakes.

Thanks Sirius for clearing the matter with cold-starts in Obsidian. And do you know how Lost Levels was tested (I mean, on which difficulties, tried coldstarts)? Being the great level set in general still seems to have serious issues on Insane difficulty and with cold-starting too. Also interested about Anthology (because I want it play it later), and TEW (how it was made so well balanced and cold-startable at all difficulties).

I don't recall the story behind Lost Levels - apparently I did do some beta testing but I don't remember what it was I was testing. I do vaguely remember seeing The Prison Compound pre-release - it may also have been co-op.

Anthology I ran through multiple times on Ace and Insane (didn't worry much about lower skill levels since I was mostly using stock robots anyway) - the rule of thumb was that I had to be able to complete it on Ace with no deaths, and on Insane, without running out of lives - no save/load allowed. I also tried to factor in that there are certain robots, particularly Class 1 Drillers, where knowing where they are simply negates them - so they have to be placed fairly and carefully. Since it's one level, cold-starting didn't really apply of course.

TEW I'm not sure was expressly designed for cold-starting, but since it was so long it's possible DFW's own play-testing for each level involved doing that. There were several other people who participated in it though, at various difficulties, to get second opinions; I recall I mostly played Ace again, and wrote up level-by-level "hot takes" as I completed each level. Most of the levels I originally thought "this is ridiculous" about are still difficult, but may have been toned down a little here and there to at least not be ridiculous. The exit run on level 24 is a notable example, where all the trap robots used to be Warlords, which in the last room before the red door is probably not possible for a normal person to survive (unless they used smart mines, possibly multiple, or still had invulnerability). The last two are now Golems, which are still nasty but you can at least dodge them without dying to splash damage anyway.
It's still playing on a knife-edge; in co-op people get caught by the Warlord in the level 23 exit all the time, and there's no guarantee they will actually survive the level 24 exit run despite the reduced difficulty, so they wind up effectively cold-starting level 25, which isn't all that much fun.
We also did co-op testing; I recall playing through with MD-1224, and that was far from a flawless run, but even a mistake-riddled run should be able to complete the set, so that helped a little as well. Particularly regarding the level 25 boss robot; initially we ran into the Obsidian level 14 problem where there weren't enough missiles to kill it if you lost some along the way. MD-1224 somehow managed to kill it with lasers and concs regardless, but the death count was pretty unbelievable by that point. I believe it's somewhat better now - at least co-op runs get past with more believable death counts.

I tried Anthology once, and found some funny traits of D2-XL - lifters (especially cloaked) became much faster, and kill you almost instantly on contact. Is it intended behavior or a bug? Also seems that maximum robot visibility distance was removed (not so important however); and for some reason baby spiders seemed faster,,more clever and harder to hit. That's why I did not get far on Insane difficulty of few initial tries. If it was possible to make robot behavior the same as in Rebirth, i would not have those problems. Also its very mazy so it is easy to get lost. And I cannot imagine how one can get through such a big level without saves, even with one or two deaths, it should take many hours to complete and I would surely forget about some trap (for example - driller) and get killed.
About TEW, I don't think that Warlord in exit tunnel can be such a big problem (once you know it is there), L24 - you have invulnerability to clear reactor room and safely exit so Golems or Warlords should not matter much. L25, on the other side, is hell. The run to boss is hell, clearing matcens in boss room is hell, and the boss itself. Triple hell. If you miss one shaker and have no cloaks on Insane, I don't know how to kill it in co-op, because it is vulnerable only from the back.

D2X-XL is a lot less like classic than Rebirth. But Anthoology, Dimensional Intersect, and Black Prophecy XL are worth trying for it. The first two in the list, despite technically being only one level, deserve to be treated as a full length mission (so no save through the whole level wouldn't be a good idea if going for no death). I don't know exactly how big they are against the largest non XL levels, but they could easily be 5x or more the size - so these 'single levels' are clearly on any entirely different scale versus all non-XL levels.

There are multi-level versions of both which are arguably better just for being split up like that (for loading times, music tracks and such).
Yeah level 25 of Tew is awful. I have managed to kill the boss after running out of shakers by sniping from the doorways with phoenix cannon but even so...
Well, at least if you decide to rage quit you've already pretty much played the mission.

The link to the split of Dimensional Intersect is dead.

Also, XL 1.16.27 erroneously cold starts you every time you return to the main hub in the split version of DI. Doesn't do that in single level version.

Anthology 3-level is fine as far as I can tell though it's extremely hard for me to cold start the D3 level (but you don't have to either).

As for music, I thought they both used default D2 music in both versions? I didn't see special custom music in the split versions. Seemed same as non split.

Yeah but you don't have the one song playing all through the (very long) game. It's still a big improvement.
I haven't seen that problem with DI split but I'm not sure I have a copy anymore either.

@Sirius Was Anthology Split designed to be compatible to cold start on Level 2 or 3?

It turns out Anthology Split has a major bug as well - the Class 1 Drone robots fire Phoenix Cannon right off the bat (second room in Level 1!) instead of their normal weak weapons! That would totally change the hardness and I have no idea what other robots could also be firing the wrong weapon.

The original Anthology is NOT like this.

Maybe Sirius himself could like to a proper split version here?

I remember the Descent 1 section being really easy. Maybe it was intentional to up the difficulty a bit like in Lunar Outpost Reloaded.
All you'd have to do is open up the mission file and delete the hxm file for level 1, and 2 if it's got one... but don't delete the third for obvious reasons.