Very good game.
Some levels are very hard. Especially the "floor is lava" levels.
I think the final boss is one of the few levels I got on my first try. :D
Sometimes it gets frustrating because I never got the feeling that I can control the movement for more than one or two shots. Maybe some type of bullet time effect where the time slows down and the player has more time to control the shots. I don't know if it would help to better see wich gun is left or right.
The bullet casing effect is nice, but those look like revolvers. :D
Loved it, the polish you put in is amazing.