NuMetalManiak

Two things to note already. In the first secret area of MAP01, you can go over the railing. On MAP10, you get locked into an area where the blue key is by blue bars, however the top two bars can be opened with the red key.

On MAP13 it's possible to lock yourself out of getting 100% kills in the shop battle. Once the bars show up to block the door, the monsters start teleporting in, but once you press the switch at the south end, the bars will be gone, but this also impacts the teleporter closets and prevents any remaining enemies from teleporting in.

E1M7: Secret sector 162 can only be lowered twice with its linedefs (697 and 698) being S1. Not sure if intentional. E2M4: First switch when triggered does not show that its flipped. E3M3: One closet (sector 120) doesn't lower, three lost souls (82, 83, 84) don't come out. E3M4: random suggestion but make it so that the teleporter leading to the exit platform actually look like it's lowering, cause I thought I was stuck. E3M7: honestly this needs to be the secret level. Way too confusing and a total roadblock for UV normies, swap it with the current secret map imo. E4M9: no music for some reason.

MAP20: Linedef 19937 has the same action as the switch nearby (5245). Not game-breaking but interesting. I now want a megawad based off of what MAP24 is. EDIT: Like with the Doomium II thread, I will mention that monsters telefragging each other on MAP30 can be a problem, especially in the last battle there.

Should mention that on MAP36, one linedef (4301) is W1 teleport. Theoretically it can be possible for a monster (or even their corpse) to teleport using this line instead of the player, but this softlocks since you need to enter the inner sector in that area to proceed. Normally it's not really practical for it to happen though. EDIT: There's also a TON of monsters telefragging each other on MAP30. Intentional?

Mods that randomize both the weapons and enemies are my personal favorites. OMGWPNS remains that case for me. This of course changes when there are changes to weapons or monsters in the WAD itself but thankfully there's options to ensure things. Most of the time.

MAP12: One hell knight (119) doesn't teleport into the map, this is cause there's no teleport destination thing for the sector tagged 23. MAP32: I was unable to access secret sector 233, the trigger for this is to get the megaarmor from secret sector 337 but the action doesn't lower the rock all the way. MAP22: The first switch (364) does the raise donut thing but it ended up leaving two enemies (one revenant and one mancubus, things 151 and 84) still stuck. I was actually able to murder the revenant with freelook.

Well, Memorial is now the 9th largest page on the Doomwiki for one. What's funny is that most of those secret descriptions were copied from the IWAD map pages with a few minor changes to them to reflect direction or items or such. EDIT: It's actually funny, I do most of my secret descriptions WHILE AT WORK.

I wish I could make something for this but I just don't have the time cause I work so much. Best I can contribute to this apart from the off-and-on playing of any maps is a concept sketch I had for a map a long time ago.

I'm taking a guess and saying that @TMD2003 doesn't actually see the pillars that get up on that ledge. That actually happened to me and I was playing GZDoom. From what I saw in the map, there's either a regular staircase or the pillars in that GIF, it depends on skill level. But there's also a voodoo doll that is supposed to be attached to a certain large tree sprite. The idea is that this tree sprite blocks the voodoo doll from moving, but for some reason, at least for the latest versions of GZDoom, the voodoo doll and tree go together over a linedef that makes those jumping pillars disappear. This isn't supposed to happen but I think it might be a GZDoom quirk overall.

I root for Our Hero of course. That infights with all of the monsters on any given map.

I can confirm most maps run well in GZDoom which I'm fine with. Can deal with mindless weapon and randomizer wad usage here (though there are others).

Doesn't work in GZDoom, though the rest of the map worked out just fine. IMO could have just made it all some timed thing.

So here's a sneak peek at my description for MAP09's Secret #5. Of course an update may make the whole permanently inaccessible thing moot if it happens.

Abattoire So TNT MAP05 and not E1M1?