From what I can tell, this is basically just a Rebuild clone. The art style is pretty nice, but the interface is clumsy and the gameplay is unbalanced. As many others have pointed out, 0% should mean absolute safety, and is very misleading. 3/5 at best.
At this point, I can't give this any more than 3/5 because it is so imbalanced. Not to mention the weird hitboxes, lack of enemy variety, and extremely low ammo. Still, good artwork, nice weapon and upgrade variety, and smooth animation.