The rough black-and-white presentation looks almost too crude to be frightening, yet the tension gets nasty once ammo is running low and you start wondering what is waiting on the other side of a door. The fully unlocked version opens the complete experience, while randomized layouts, permadeath, corpse recovery, terminal puzzles, and instant-kill hazards keep every run feeling a little precarious. It is the sort of game that can make you stop after clearing one area, not because you are finished, but because you need a minute before opening the next door.