Not a bad game. It definitely could use a bit more work. More levels, more upgrades, since the last like 5 or 6 levels kept saying new upgrades, but nothing new is there. I beat it, but now all that is left is leveling up to max. The only other thing I would say is some kind of save or checkpoint feature. It's a bit irksome to constantly restart at the beginning every time.
Still, would be a good candidate for a sequel if there could be one. This one was good. Maybe add some plane types and a few other things and it'd be great too.