Would be very nice to have a pause after every wave, when a slower wave is followed by a faster one thy intermingle and the guns aim at the first wave first so the faster wave gets through. Also would be really nice to get an nice aoe weapon capable of doing real damage to those linking guys.
Nice game, but it's really long, I mean, 74 levels! Also, it's kinda repetitive, if you ask me. But it's not too shabby and is very original. Nice job! 4/5