You can't escape Doom. After tearing open a portal to Hell on the Source engine , it's aiming its slavering maw at the roguelike genre with DoomRL , where you'll have to escape a dark and infested facility of demonic horror while also worrying about the looming threat of permadeath. No pressure or anything.
All the roguelike trappings show up alongside sound effects and graphical sprites lifted directly from the FPS. You'll frag beasties in quick, turn-based battles while scrounging for ammo, health, armor, and keycards. Three classes—Marine, Scout, and Technician—determine your stat spread and passive traits, and there are over 30 randomized levels and mod support for extra user-made floors.
DoomRL already has a dedicated community talking shop and contributing content over on its official website , and the latest version, 0.9.9.7 , released yesterday after a little over a year in development. You'll probably want to brush up on the game's wiki as well before jumping in.