If the game freezes, just click inside it (games can get unresponsive if you click elsewhere on the page).
Enlist in the S.W.A.T. faction and enter the role of squad member "Jack". Use cover for a tactical advantage, fight your way through waves of terrorists, and earn uber-sick weaponry as you progress through the levels.
Mouse- To aim, left click to shoot.
Arrow key- Fire Tranquilizer.
Shoot on power ups to pick them up.