I don't know if it was because I have a 16x10 ratio instead of 16x9, but most of the UI on the death screen overlapped, and sometimes you could get hit from behind and not know why you died.
That being said, the rest of this worked really well together! The art style and audio style complemented each other, and I liked the responsiveness of the gun. The chat feature was also pretty neat and I liked that it affected gameplay.
Nice job of picking one mechanic (timer = health) and making everything else revolve around it!