This was fun to play!
For improvement: it would be nice to see your score after you loose (some sort of loose screen, or a "last score" field in the main menu. Also, I closed the game on accident multiple times, when I reloaded the left gun after I died (since you reload the gun with the same button as you close it) (also, getting negative score is kinda weird)
In conclusion, the game was fun to play. It is quite challanging and I played it till my hand hurt (yeah, I spam/reloaded, since I discovered that there seems to be no cooldown )! Also, my brother who was in my room when I played it liked the music (I liked it too, to be honest).