Well, it's got a similar vibe to The Fantastic Game.
If I had to pick my favourite room, i'd pick the wavy room.
The AK makes me want to bunny-hop like Counter Strike, but the gravity is very high.
But yeah, you can break out of bounds, there's no real feedback when you shoot a zombie with one bullet, and the prison is large. Like, very large. You'd benefit from shrinking the map size, slowing the player down, and speeding the zombies up. This would make it more tense, because as it stands, you can trivially run past any threat.