i really like the concept about having to be hit by specific bullets in order to damage enemies, and the art is pretty cool too. however, the game does tend to be really tedious as you go on. levels require you to have a specific number of hearts in order to proceed, so accidentally hitting one bullet will have you waiting to die just to restart the level again. maybe if killing an enemy granted two hearts instead of one, it would make this a lot less painful? i think a colored timer for what and when an enemy will shoot would be great as well, since dashing to a broken enemy only to die to a bullet they just fired 0.1 seconds ago sucks. personally, i think dashing according to your mouse might control a bit better, though that's just my opinion.
besides all that, though, it's still an interesting game with a cool concept that has the potential to be fleshed out a bit more! on it's own right, it's still impressive :)