Played through the web version and I liked it a lot.
The game starts out easy enough and ramps up nicely, with different enemy types. I find it clear what the power-ups do from the description and interesting that they're marked in the ammo bar for when they do activate. However it seems like some markers don't stack in the ammo bar, i.e. they disappear once other markers are in, if that's a bug I don't know but the power-ups still activate.
Would be nice with a better victory screen. ;-)
Graphics are simple yet effective and expressive. Quite juicy. Music is a bit simple and currently a bit too loud, some sound effects are hard to hear at times.
Short but really sweet! Again I liked this a lot.