Well...enjoyable.
I GAVE YOU A 5!!! But it's not like you don't deserve it. Except for your, ehem, handicap (that didn't sound right) . Three words: OPTICAL. COLOR. MIXING. People don't find constant yellow annoying, but I do. So:
red+yellow=orange
red+blue=purple
blue+yellow=green
Plus toning darker by adding blue and lighter by adding yellow.
I didn't expect a shooter, but a retarded...shooter...puzzle...maybe. So, yeah, that was a pleasant surprise.
Controls were okay, but maybe (if you couldn't do mouse controls) you could make arrow-turning more sensitive and/or at least a dot to show you where are you shooting (that would help when you're just out of the enemy's line of sight or behind a wall trying to point him).
Wow, that's the most enormous amount of letters I seen myself do in a while. So, since I tried to write that much please consider my suggestions. Thank you. See ya. Awaiting other games.