Mmh...
over all, there's nothing special to it. The Music is fun at first, but gets annoying after a while. The waves are just... you know, you just hold down your mouse button, you dont have to aim really, there are no real differences between the enemies... and the different weapons are not that different. Why is the Shotgun not shooting more than one bullet? Plus, some bullets seem to disappear in midair.
If you tweak here and there, this might be a good game thought!