This is one of the best FPS games that I ever played. This is how you do a FPS. You have in this game that pace which doesn't exist in other games. You have lots of fun kicking and slashing and grabbing and shooting down enemies. As a player you have alongside you some teams mates who can help you in your endeavour: to escape a crazed planet and take revenge.
You have the opportunity to upgrade your weapons at your dropbox. You can buy plenty of ammo too.
You can get points by ingeniously murdering your foes.
I won't tell you the story (it's not much), but the game is FANTASTIC.