Really nice Game you made in this short time, I hat a lot of fun playing it, loved the Art style, Concept and music (and basicaly anything else :D).
The only problem i had was the following: I didnt know when and where Enemies would drop from the sky so when the bullet was somewhere on top it was always a little luck gamble if an enemy would fall right on my face while grabbing the bullet. I would suggest showing/marking the spot where an Enemy will fall down maybe 1 second before he does.
Very polished game tho. I'm impressed