Not too bad, but I am confused.
What exactly were the powerups supposed to do? Also, the fight with the energy demon was very confusing, as the orbs kept warping around the screen instead of going along any path, making it very difficult to collect them. In the end I was just flying around, boss not even at half health, and I won....I don't think that is what you had in mind, so I am giving you an overall rating of 8. The game was ok, and just as it started to get boring I reached the end, and at least the background changed.