thoughts; the coins fly off the bottom of the screen, but it's a top-down game? The bouncing blue ball isn't explained in the instructions. Took a couple of waves of avoiding it to notice the regen effect it had. Shots aren't very visible. Otherwise pretty slick.
weak sauce. blurring effect of enemy movement and projectiles is disorienting against the background. One life isn't so bad seeing as there's no additional content to the game that I could see. Die once and you've probably already seen all there is to see.
The costs for things don't really seem to line up to the benefit. Some things are stupidly expensive but don't even provide a visible increase beyond the number. Regen, for example, goes from 0.10 to 0.11 on upgrade, but there are so many shots coming in that standing still doesn't help to regen as you'll be taking damage faster than the regen.
Fun fact: resizing the browser makes you invulnerable. enemies can't hurt you, you can't hurt them. Resetting the browser size returns things to normal. Did this until the boss fight, beat the boss, returned to invulnerable.