I put some info from the game:
-1 player game (of course)
-2 player game
-Lot of aliens, like eliminators, bitters, basic aliens...
Lot of fun if you gotta friend..
I thought that the game idea is brilliant and me and my friend played it for ages. My only problem with the game is in two player, the keys set to change player 1's weapons are annoying and badly mapped.
Instead try using the 'Num Pad' for player one next time...key up the good game making!