Well..
This game is kind of dull, because this concept is something that 99% of all flash makers have done. It has been seen before at least a thousand times on newgrounds.
But when that is said i must say that i like that its spiders, and not spaceships :-)
You could have used a few more minutes on the graphics, it seems way to rushed, actually i get the feeling that you made this by rushing through a tutorial.