Pretty fun game, and I specially liked the music with all the sonic sound effects, wish more people realized how much potential sound effects from other games like those have as instruments.
Althought I wish enemy spawns were telegraphed somehow, at least with a sound or something like that before they appearing, because it happened a lot of times me being in a wall corner and dying because somebody spawned there suddenly.
Also I think the tank is bugged, he wasn't dealing damage when I tried using him.
Anyway that's my best score, couldn't survive much more than that on the madness x)