Pretty Good, but could be better.
I think this game is pretty good and addictive for about 10 minutes. Then it starts to get a little boring. I think there are some improvements that could be made.
1: Make boss battles with really hard bosses that are unique and extremely fun to destroy.
2: Make a few more upgrades that you could get for your ship.
Besides that, this game is pretty good. Just some suggestions for a update of the game if you are going to make an update.