Complete Hearts and Minds Campaign.

Complete BOOM!

Climb a chain link fence and rejoice.

Perform melee finishers on 25 Creepers (single player only).

Make an enemy kill themselves while shooting at your Shell.

Keep Berserk active for at least 21 seconds in one use.

Buy out any one Upgrade ring.

Put an end to the threat, once and for all.

Make it through to the lair.

Open up the secret entrance.

Find out how to reach the lair.

Kill 100 enemies while in the Marauder Scout Walker.

Destroy the Jamming Devices.