Excellently addictive little game. Love the retro Tron vibes and simple controls for a simple gamer. The art style, while simple, worked perfectly and did not just feel like programmer that wasn't finished. The only real criticism I would have is it would be nice to have some indicator that discs are about to change.
Couple of things I would suggest, power ups or multipliers for things like getting two discs in quick succession, similar to the current chaining discs of the same colour mechanic.
Would love to see a version of this game that you worked on for longer.