Second, if you are stuck in an unfair custom map on nightmare difficulty, and there are literally too many monsters to continue, instead of using traditional cheats just type:
spawn mech. It will bring an armored mecha robot (where you can get in) and use 4 powerful weapons to restore balance. If this is not enough (or you are bored) try to jump and squash enemies Metal Slug style!
Last, a long time ago, I wrote useful script to run gzdoom with various configurations/wads.
or the only ↩