This was actually loads of fun. Good theme integration, I would have liked to see the art represent the theme a little more, It feels like robots, or even circuit boards would have been more thematically on point than zombies. The atmosphere is very good and suits the horror vibe.
Did I notice some dynamic music switching? very nice.
Oh, and special note to using the 3D black walls as a visual sight mechanic for the top down 2D.