The game is certainly interesting, giving you lots of tools in your disposal. Simply surviving is easy, but getting a good score is not, so that's nice. I find that enemies are really bad at attacking your crystal, so there's not much incentive to protect it, especially in the later stages. Sometimes my vision gets obstructed when I'm at the bottom of the arena. The knockback mechanic is borderline useless when all enemies are ranged in nature. It's a very interesting game.