The use of 30 colors gives it a gradient feel and makes it look very ugly in my opinion. try toning it down to about I'd say a max of 15 colors, that should be overly sufficient for that piece.
Pretty cool animation!
I agree with Ndsfreak here, it's a small pixel art so you could definitely get away with using less colors. Dithering can be your friend if used the right way.
If you feel like it, you could give up some of the extra green colors and some of the less used grays for the weapon, and adding a bit of shading on the eyes to match the shading style you used on the rest of the image. :) It might actually make it look more cohesive.
How come know one ever made a comment on this funny animation :) WEll let me be the first. I really like it. The gun is great and also love the laser from it. Also good wotrk on the shading :)
How did you do "frames:" in the information? or whatever it is... btw,awesome idea! :D