Big Al's Scooter

Big Al's Scooter is an Achievement in Halo Wars that is unlocked when the player beats the AI in under 10 minutes in a Heroic Skirmish game.

It is worth 10 Gamerscore

Methods
Enter a 2v2 Multiplayer game with a friend on the same team. Set the other team with two AIs on Heroic or Legendary; it doesn't matter which. When the game starts, have your friend exit to the Xbox Dashboard. The game will automatically end, declaring you the winner and unlocking the achievement.

Enter a 1v1 deathmatch game against the AI on Heroic. Use the Prophet of Regret and the AI as the Brute Commander or the Arbiter. Right when you can, create the Temple and the factory. Create five or six Locusts and send them and the Prophet through the teleporter. Head straight for the citadel and destroy any building the enemy is constructing. Do this right and you can get the Penny Pincher achievement.