So much criticism has been addressed to this game, yet I got it for just one buck on Humble Bundle. Therefore I played it. And I am not sorry for it. All right, it has its letdowns. It hasn't got that clear graphics and it is all cliché, but what did the game expect? You just shoot around the aliens that invaded the Earth. You have the classical guns from all the other shooters. The are there some interesting shootouts, difficult bosses (not the last one, sadly). There are jokes and some hints to other games or to other companies.
Overall,it's a forgettable game, but you can enjoy its shooting.