The objective is to survive within the restriction circle because if you go in the red, your little character will start bleeding because by the looks of things, the area is radioactive. Not a whole lot of other players online but if you can get some people with you, you can fight against other players.
Move: W / A / S /DRotate / Turn Around: Mouse moveShoot: Mouse click / Space barAction: EView Map: QReload Ammo: RUse Grenade: FUse Item: G
Having a team is strategy tip number one. And you don't want to separate from your team.