A decent game.
Shooting is enjoyable enough and the idea of having to let your health tick down as quickly as possible is an interesting spin though simple.
The movement is good although sometimes aiming feels a bit sluggish.
The aesthetic design is pretty basic but it works.
The choice of music is fine as well, wish there were some sound effects when shooting and being shot at though.
If the enemies respawned sometime after being killed, that would be a good way to keep the player on their toes and it could sometimes be tricky to see where enemy shots were coming from (mainly in level 3) as they blend in with the floor.