It's Galaga. It's not Halo 3 or something else with great graphics. It's Galaga.
You shot the enemy that look like the classic arcade game you grew up shooting. If you never played Galaga before, then I don't understand why your getting this game anyway. I'm not going to go out an get some 1980's game that I didn't play in the 80's.
But if I was going to complain about this version. The only thing that I could say is that I wish it had different difficult levels so that I could play it on easy get some extemely high score and just play without some of the flustration that you get from the version being gear up to a higher than normal difficulty. But not so difficult that the game isn't fun.