Real cool stuff
This game has the potential to be great. You have the coding down but now its just a matter of cleaning things up. I think you could have put some more effort into your main menu. Also I would suggest switching up the units coming at you and have them come in waves (as opposed to the constant flow). What I liked most about the game was the option to play with two players. Overall I think you have a decent game here and its being underated.