The rules are simple, destroy the gems with your handy laser beam, but make sure the gem you are destroying is the same colour as your laser beam otherwise you’ll get shocked and unable to shoot for a couple of seconds.
But keep an itchy trigger finger mind you because the longer you play, the faster the gems start appearing. If any gems are outside of the playing circle, you only have a short amount of time before a five second countdown starts and when that happens, it’s game over!