First of all, wow, that art style is really clean and works well with this game - nicely done. Second, well done on making a complete game in a single week, very nice. FPS is not normally my jam but I powered through two dozen levels of this game... woot! I also liked that the projectiles on both sides were slow enough to dodge, and yet still felt really satisfying in the throwing.
The primary thing I would want is a little more balance - I'm a horrible FPS player, but even I found the first dozen levels pretty easy. If it were me, I'd experiment with dropping the HP of the early level foes, but increasing their damage by a bit. You might want to check on the pathing as well, as there were a couple times that groups of foes seemed to be stuck behind a cluster of rocks or trees and they didn't unstick until you came around and shot them. Lastly, hiding behind cover seems to be way too rewarding for the player, maybe add an enemy that is a fast moving melee that will flush them from cover? or enemy grenades that will force a player to move before they explode? You're the devs, I'm sure you'll think of something.
Oh, there was a loading hitch the first time you hit an enemy... I suspect if you pre-load/use the shader before the combat portion of the game starts that should eliminate that.