Come on, now!
Honestly, this was not very good. Not really original, they were only 3 kinds of ships for every level (that is not very variating) and it took an eternity of pressing a and s to just get to the boss and then another eternity to finish "him" of. The game is only hard if you don't want to severely punish your left hand.
The game is not very graphic either, making it kind of dull. But I guess it's not THAT bad, though. My expectations were pretty high, because I thought it was about INVADING other planets, not just to take down their defenses, but to take on the fight on the different planets soil with milions of soldiers in a huge epic fight. But... yeah.. Good game for being flash, anyways. :)