Brilliant! I didn't think of this much at first to be honest. When I started it and realised that the character wasn't moving freely, only hopping between two possible spots while shooting enemies, it seemed very limited to me. Everything was happening in this confined area without the possibility of going anywhere. That early impression wasn't fair. As it turned out the strength of this game lies elsewhere.
The gameplay is generally about shooting swarms of enemies with your character's powers, who can fire magic missiles from his hands at really high speed. Lots of sweeping action as you clear them out while dodging them when they charge. Music plays an important role in this game and while I may not normally listen to this sort of music, it's very appropriate for such a fast paced game.
The real fun comes from obtaining new abilities and learning how to use them effectively to become even better. In fact... Every ability you unlock is something new, but having a big impact on the gameplay. It forces you to change your habits to get used to the new mechanic, as it gives you decisive advantage that helps you make even greater progress. The abilities are unlocked along with new music tracks that you collect as you play and once you have them all, you can also obtain a secret ability (if you figure out how or look it up) which leads you to possessing unbelieveable power that you'll need to prove your true ability in the Endless mode.
Overall this was fun!