Here's what I have to say
Pros:
-Good pixel art
-Music slaps
Cons:
-When the videos said "make the guns have impact", they didn't mean have the gun shake the entire screen and destroy your speakers.
-The enemies falling from the sky is annoying and unpredictable, having them come from the sides of the map in waves would be better imo
-I didn't even know there were powerups until I read the reviews, some hint popups to indicate what things do would help.
With some polish this game could be pretty good for a browser game.