Steam Early Access is now available for room13, an over-the-top action/platformer for Windows from a one-person development team. This is described as a "horror styled, arena shooter, where you construct a new weapon every game, slaughter the dead, and can wear a reanimated shark’s head as your face because why not'." That seems to cover it, but in case it doesn't, here's more:

Travel room by room emptying your clip into hordes of the undead as you unlock the secrets of the labyrinth you find yourself trapped in. Unlock new faces, customize your weapons, collect zombie chunks, battle bosses, and unlock the mystery of who you are.
Gather enough zombie chunks (remains) and you’ll earn a battery. Get three batteries and the round ends, the doors open, and you can venture into the next room, or search for more weapon parts.