I just played your game, and I have to say, the graphics are awesome. Thats part really stood out to me! I like the effects and the pixel art!
One thing I noticed is that there is no directional shooting/aiming ,and I didn't know where to find the bullets. Maybe adding a tutorial could help improve the experience! Then the enemies were pounding on me like I am a sandwich 0-0 Prob adding a more of a linear approach to the difficulty could be better! The game wasn't 100% on theme but that's alright :D
Overall, I had a great time playing.. even tho i didn't know where IS THE DAMN BULLETS xD ,and I can see the potential here. Keep up the awesome work!