The core of the game revolves around shooting crystals that split your beam into a green energy beam that charges your jewel meter, and you can get insane score through multipliers once your meter is fully charged. If you die, the meter resets to the original multiplier and you need to build it up again. It's really fun if you want to aim for scoring. Powerups are easily abused if you're just going for survival, especially the blue shield powerup, so I don't recommend that. I had a much better time when I aimed for score.