Its good

But Eclipse914 is right, You need more variety. Maybe you should add an upgrade feature, and even different types of enemies.

Needs variety

I think its alright, really, the sound is good, the gameplay is alright, the graphics are good but it overall needs more variety. The enemies all pop up in the same places, so its almost as if youre killing the same enemies over and over again until you reach the killcount of the level. Overall its good, but the lack of variety in the game made it kinda bland.