This was my first encounter with turn-based tactics. You control a team of combatants that should move around and kill aliens. Mostly the tactic was, move one guy forward and if he sees anything, move in the others behind and let them kill the monster.
I can't remember this game to have any story, just a set of missions that you could carry out in any order you'd like. Even if the game play was fun, it doesn't feel like you're fighting for anything.