A dungeon crawler where, when your character meets an unfortunate fate, depending on circumstances, it could leave a static lootable pile for others to discover, turn into an NPC monster for others to defeat, or disappear forever.
A text-based exploration game with a dodecahedral map, like the classic "Hunt the Wumpus", but one room has a down staircase that leads to another, concentric dodecahedron, which you can explore to find another room with another staircase leading down...