Cool twist on the space invaders formula. Can be taken to interesting places: 2player alien vs ship, different shots for the different types.
Only major issue is with selecting "Your" alien I understand why it was grayed out (as the others are white) but it make it that my eyes were not drawn to that player. Took me a wile to figure out maybe scaling the sprite up would have worked. Also it would have been better to be able to not select the dead alien locations when changing as well as jump to a close alien when you died (probably a time issue).
There are other improvements but I know they would have definitely taken some time to do.
Well done I had fun.