FLEOHSIS didn’t look like it would be a playable game in time for the end of the challenge, so I invoked plan B: a really basic text roguelike with a simple concept.
In Corpse Stacker, you’re trapped in a 10-by-10 grid, zombies regularly appear at the edges, and when you kill them they stack up on the ground. You win if you build a stack of 10 zombie corpses. You lose if they eat you first.
It requires Python (2 or 3) to play. There’s also a standalone executable for Windows.