A good old game that only brings me good memories. You have 3 storylines that have extra episodes that can be unlocked if you complete the levels in a certain difficulty. The 3 storylines belong to a Marine, an Alien, and a Predator, each one has his special abilities. Some levels are pretty hard, I even got lost in some, some others I got caught by surprise (I'm looking at you, turrets!), but that's one of the reasons this game is good, as most of the classic games.