Go check out the latest version:
I'd still like to keep this version up for posterity's sake, but the version up on Kongregate is much more polished and complete.
Arrows Keys - Move
Space Bar - Shoot
C - Color Change (No gameplay benefit but it looks cool)
Try to collect the five keys in each stage and avoid/kill the blue and green guys (They can grab keys too).
Inspired by an old C64 game called "CrossRoads"