Wow, really good fun blasting stuff game, with "simple" but effective graphics.
Upgrade shop was well balanced to replayability. I focused on recharge rate, after getting my multi fire up a bit first :).
I assume all those projectiles are game objects? as my game got a bit laggy at times, freezing up for a short while.
Wasn't sure at first that being able to shoot the projectiles was a good thing, but it really added a good extra element to the game!
One thing I think it needed, would be a kool down period after taking damage. An Invincible 2 secs, after being hit. So you don't get spawned on top of, and loose all health rapidly.
A second thing would be to ensure a zone around the player doesn't get randomly spawned on.
Fantastic job, one of my favourites i've played. Hope you look to continue this game.
Well done