I really enjoyed this, also works really well in browser for the most part until there was just too many enemies and it started lagging lol (I am certain this is not your fault though). Two recommendations are to one add particles when enemies are hit so I can see my bullets, and to make it so you can't accidently pick a power up when the screen comes up, this happened to me a couple of times. Nice variety of enemies, and it's you included menus with mouse sensitivity (still so mad at myself for not doing that for my FPS lol).