Really great game! Just a few small critiques that could easily be fixed .
1.When you get he blue power up and you shoot really fast, pretty much all the sound effects cut out.
2. You should make a separate icon for each powerup. I got a powerup I didn't end up liking and wished I could switch back to the other one, but the icons are all the same so I never knew when I was gonna get the other one back.
Besides that, I had a lot of fun playing this.