Get 250 Headshots.

Kill 25 enemies with Ground Pound.

Retrieve the Power Source.

Destroy the Orbital Gun.

Get 100 Headshots.

Fight your way to the crashed Rok.

Kill 10 'Ard Boyz.

Multi-kill -- 5 enemies with 1 Frag grenade.

Kill 4 enemies with 4 shots during a slow-mo breach in Single Player or Special Ops.

Good guys stand up and take the heat.

Bought a seriously expensive car.

Acquire a car manufactured in 1959 or earlier.