Well done!
I think the music is really good and I really like the particle effects, it really adds a lot. Also I think the sound effects of the voice is cool, although the voice seems to change, which feels a bit strange as its the same character speaking.
When I shot and have the gun rotated to the top left, the bullets collided with the player and were not shot out. I also think that it was a bit unclear how I won a level, did I need to kill a set number of cubes? Or did I need to stay alive for a set period of time. Showing this with either a timer or score I think would help.