I hate the generic building map

[Elementyo]

It's just so tight and limited, and the bodies start to easily clog up the doors

[hello]

I totally agree, it seems too out of place in a game with mostly open maps

[MantarTheWizard]

I find a good strategy there is to get into the j-shaped set of rooms with the pill at the end, and use the enemies' bodies to block the door. You can sit behind a doorway (walk mode helps) and let the doorway block most enemy shots, and the bodies keep them from getting in at you, while you blast the ones further out.
You have no way out, but you do have about three doorways to fall back through before you're caught. It can be tricky to get back out if you need to grab a heart, though. I usually try to wait for the corpse blockade to vanish, then explode and make a run for it.

[DASH.RABBIT]

+1 to changing the interior building map. The bar too, maybe. Both are way too tight of spaces. Worst is the generic building though as there isn't even high ground. If you're caught early-game or with the wrong pills, a full Scary Rolly Boi wave WILL back you into a corner and kill you.

[Pango Pangolin]

this game is friggen impossible.
unless you get a shop, your run ends the moment you leave the first level