You got in the tank with two other players.
You killed 200 enemies.
You completed the game on Black Ops difficulty.
You completed the game on Suicide Mission difficulty.
You rescued all of the POWs in the game.
You found all of the Secret Areas in the game.
You achieved the 12X score multiplier.
You achieved the 24X score multiplier.
You freed 25 POWs.
You attained a 24X score multiplier on every level.
You completed the game with at least one other player.
You killed 40 enemies while in a vehicle.