I wish there was an option to make the planets invincible even if by a short amount of time. I would use maybe a shield that autogenerates faster and gives the planets immunity to friendly fire and then, once they're unprotected, they would take damage from friendly fire, until the shield regenerates again. Alternatively, shieldless planets could autogenerate the shield faster if you shoot at them... Decisions, decisions decisions. You definitely nailed the controls and the upgrades are a great additions. I didn't like the music very much, specially the way it starts, but I understand this may be a bit personal. I would discard the first 30 seconds and/or increase the tempo, this is a space shooter, not a space funeral (although if you could see me play, I really died a lot on this one, but I kept playing). Thanks for making this, I had fun :)