After reading the DeHackEd request (I kinda like it, BTW) and the 'play DoomRL in DoomRL and break the fourth wall completely', I had a silly little idea that may actually mean something; simulation terminals!
Basically, these are & signs, which, when used, provide you with a choice of weapon, and and difficulty level to play in. The weapons are:
* A plasma rifle with infinite cells, overcharge disabled, and EE 2,
* a fastload double shotgun, Hellrunner 2, and infinite shells, or
* a chainsaw (4d10), and Brute 2.
You spawn in a Halls of Carnage-like zone minus the lava and soul spheres in plasma rifle challenges, Hell's Arena-esqe for shotgun and chainsaw.
The difficulties are:
Easy: You regenerate one HP every second, and:
*Plasma rifle: have to fend off human captains that have EE 1.
*Shotgun: have to take out a high amount of hell knights. It's easier than it sounds, trust me. :)
*Chainsaw: rip apart cacodemons. Fun, eh?
Medium: You regenerate two HP every second, and:
*Plasma rifle: have to mutilate former commandos with EE 1.
*Shotgun: turn mancubi into pools of blood.
*Chainsaw: annihilate hell knights.
Hard: You regenerate three HP every second, and:
*Plasma rifle: Have to kill lots and lots of arachnotrons. Oh lawdy.
*Shotgun: Also arachnotrons. Have fun.
*Chainsaw: Barons of hell, and pain elementals. Good luck.
Blade: Same as hard, but you don't regenerate HP. Only do this if you like suicide.
You keep 33% of the XP you won in easy, 50% in medium, 75% in hard, and you keep it all in Blade.
There's no risk of death here, but time will pass as normal when you're playing the simulation. The game will alert you when enemies appear. You can pause by hitting the @ key.
So how are you going to flame me to death for this one? :P