Update: The contest is now closed. Winners will be notified shortly!

Don't want to wait until next week to play Halo Wars? Well, how's tomorrow sound? While the demo won't publicly available until next Thursday, Shacknews and Microsoft have teamed up to give away 15 codes that'll let you download and play it a week early.

If you're hoping to give the Xbox 360 strategy game an early go, just add Halo Wars to your wanted list with the above widget, and post something in the comments below. We'll randomly select the winners and send codes via Shackmessages tonight.

The final game from soon-to-be-closed Age of Empires creator Ensemble Studios, Halo Wars hits retailers on March 3. The downloadable demo packs two optional tutorials, the first two campaign missions, and a multiplayer map for offline battles against the computer, in which players can control either UNSC or Covenant forces.