Not bad

It seems like you were trying to combine the "Raiden" games with the traditional "Space Invaders" game. While the graphics were pretty impressive, the main flaw is that there is not that much detail. It can get a bit repetitive but that is the point. I wish my projectiles could reach to the far back of the screen. The sound was alright and so were the sound effects. You definitley have a good start and it is hard to believe that this really goes on for 20 levels, given how hard it was at first.

it reminds me of space invaders

that game itself was a good idea but the gameplay and the mechanics were too much like that old game space invaders.