peach freak

I'm glad I'm not the only one that thinks that's a building too!

I largely play on Chocolate Doom, but the thing I'd want the most is probably an active kills/items/secrets count, since you may not realize playing vanilla you didn't 100% a map until you exit the level and see the intermission screen. Also, I have fun customizing the Automap colors on some source ports.

E2M9 uses an exit teleporter while the secret exit in E3M6 is a switch.

TNT Map07: There are two sets of Shotgun Shells right behind you at the beginning of the map. I've been playing TNT for over 20 years and just found this out. I've never bothered to turn around since your first instinct is to run down the hall and grab the Plasma Gun, as it's the first Plasma Gun you can grab in TNT. While it's only two small ammo pickups, I'd imagine it would make a HUGE difference for Pistol-starting the map, since ammo in the opening building is pretty scarce and there's several high-HP enemies in that building (a Baron of Hell, some Hell Knights, a Pain Elemental, etc).

TNT Map04: Was playing this map the other day and decided to investigate that constant lift stopping sound you hear in those two northern triangular rooms (where you teleport between the "normal" and "alternate" dimensions of the map). For a while I thought something got stuck on a lift or something, but there's these two sectors off the map. Each of these sectors have a ceiling that's only 4 units off the floor, and when you walk into the into either triangular room from the south, you'll walk over a line that activates a crushing ceiling in those two off-map sectors. Since the ceiling starts off so close to the ground, it hits the floor and rises back up 4 units pretty quickly which is what makes that constant sound. I've circled the two sectors and the two walkover lines that trigger the crushing ceiling in those sectors: If you want to test this sound out, I'd use vanilla/Chocolate Doom, as this seemingly has a different sound across different source ports.

I've never looked at this part of the map with a map editor, but I've always noticed that lower sky because the Imps up on those platforms in the back won't see or attack you unless you get pretty close to them, and you also can't attack them unless you're almost directly underneath them. That intended design actually looks pretty cool, as I said, I never knew those upper MARBLE textures were in place.

Speaking of Plutonia, in Map10, I knew of the Yellow Door skip, where you can run across the Yellow Skull stump next to the door and into the window, getting you past the Yellow Door and early access to the Red Key (which allows you to skip most of the level). What I didn't realize was that monsters can open that Yellow Door from the inside (the door doesn't require the Yellow Key from the inside, if it did, you would be trapped inside that room if you did the skip because the window floor heights are 25 units off the floor of that room, meaning it's one unit too high for you to get onto). That means the alternative way to get inside that room without the Yellow Key is to have a Chaingunner inside that room open the door for you. Get in front of the Yellow Door and be sure to cut off the line of sight for the Chaingunners (as they'd fire endlessly at you if you don't) and they'll eventually make their way to the door and open it to get to you. This is an easier skip if you're having trouble running over that Yellow Skull stump (as you don't have too much space to maneuver with it).

Yeah, that's a common theme in Plutonia, you'll often find smaller items stacked like Health Bonuses or Rockets, so you'll pick up like 5 or 10 of them instead of just adding one 1% health or 1 rocket.

The most hilarious RNG I seem to get is if it takes three Berserk punches to kill an Imp, that tells you the first two punches were both the lowest possible damage roll of 20. What then makes the kill unsatisfying is that if you don't gib it with that third punch, as it's much easier to gib an Imp with 20HP remaining with a Berserk (60+ damage roll needed) as opposed to full health (140+ damage roll needed).

Plutonia Map29: You can run into these windows in the corners of this room where the Chaingunners are from the floor above. This is that building across from the building where you get the Rocket Launcher (that has the trap of releasing several Demons once you pick it up). Of course, running into this window will softlock you and trap you.

In some of my maps I've used the insta-lowering trick for "unlocking" doors without a key. The downside to putting bars in front of a door is that you can still open the door if the bars are too close to the door. In front of the door, I create a sector that's one unit wide in front of the door and raise it to the ceiling, putting the door texture as the lower texture. To "unlock" the door, I have a switch that does the "Floor Raise to Lowest Ceiling" action where the sector will insta-drop to the floor, revealing the actual door behind it. I used bars in front of these doors, but the switch that's highlighted will both insta-drop the bars and the fake door sector, using those dummy sectors in the top left. As you said, the "floor lower to lowest floor" action is too slow, especially given that the switch is in the same room.

Doom E2M2: You can press any of the four walls (not just the wall with the switch) in the secret area with the Soulsphere next to the Blue Key to lower the secret back down to the floor.

I think the thing that I lowkey like about the episode 1 level designs is that a lot of barrels are pretty well-placed. Few things are more satisfying than cleaning out an entire room with a barrel explosion caused by a single shot.

Speaking of Map32 of TNT, and this isn't something I just found out (I believe I found this out in recent years only because I was going for 100% items), but it's still an easy-to-miss hidden area. At the end of the map, there's a hidden Megasphere with a Revenant. You need to go into the tunnel and face the switch that opens up the final area where the exit is. Turn right and there will be a fake wall across from you. If you walk through it, you'll find that hidden room. As I said, it can be easy to miss since it's not considered a secret area, and if you're going for 100% items and end up missing one here, this would be the most likely cause.

Adding to this, when I play Map32 of TNT, at the end of the map I have the Cyberdemon infight everybody instead of me shooting them. By the time the Cyberdemon has killed everything, I have a ton of Revenant homing missiles chasing me, when I steer them into the Cyberdemon, the Cyberdemon will shoot briefly at the Revenant corpses before going back to attacking me.