Cool. Nice short game. Would be fun having it longer, but so far it's a nice concept. It being hard to control was part of the game, imo, as opposed to a defect :)
Holding down space makes my browser (Opera 12.02) scroll down the page, which ensures I don't see how much power I'm shooting with. Any chance of changing the button? The game reminds me of a monkey game that I played with on the 386 :D
No way to restart when you die other than reload the page.
No way to upgrade the towers.
No way to pause the game.
No info at all on the screen to tell you what to do.
I would give it zero if I could.
Automatic heal upgrade doesn't add any health points whilst losing health, or when not losing health. It doesn't do anything, but take your money and run.
Shoot button changed to Z. :)