Lags on a slower machine, primitive gameplay.
This is a nice try, but between the slowdown I get when there is too much on screen and the gameplay that seems to be a poor derivative of Defender circa 1981, this needs a lot of help. Rethink this and reprogram it. I'm not sure if it's the sprites themselves, the pathways, or what, but something needs fixing to even get this 5/10. Then reconsider the gameplay itself, and put in some sort of plot if you want more.