Cool game! :D
I like the art of the player and I also think that the music is really good. Also I think the particles are well implemented.
One thing that would improve the game is to make the player be lower down in the camera (right now player is at the center), as it was difficult to see the enemies who were shooting at you. Also the icons for the health were a bit too big and placing them in the top left corner was a bit distracting as it was difficult to see, I would recommend putting them at the bottom, as there are no enemies there.