A variant of Nethack. Slash'EM (Super Lotsa Added Stuff Hack -- Extended Magic) is generally considered harder.
You can find it here. Be aware, though, that there's been no development on it since 2006.
Has nothing to do with Slasher Movies, or Slash Fic.
Tropes used in Slash'EM include:
- Most, if not all tropes in Nethack.
- Bottomless Bladder: Averted. There are toilets, but their use isn't obvious at first. If you're Satiated and sit on one, you "take a dump" and lose some nutrition, along as being cured of sickness. It is extremely likely someone will never use it anyway, but it's there.
- Did You Just Punch Out Cthulhu?: In a earlier version of the game you could literally do this. He's ungodly strong and respawns anyways, but you know you want to try.
- Ki Attacks: Monks get them.
- Laser Blade: Yes, you can wish for a lightsaber. Remember to turn it on first.
- Lethal Joke Item: There is an artifact spoon called Houchou that instantly kills whatever you throw it at, but it breaks afterwards.
- Schizo-Tech: Soldiers now carry various guns, most of which use the same ammunition. However, no other enemies carry guns, and you are eventually going to run out of bullets...