Chuck's Ducks 2 players that link their Xbox Live accounts to their Facebook profile can unlock a new difficulty level in the Crackdown 2 demo that hit Xbox Live earlier this week. Earning enough points in the Facebook games can also unlock a new duck-based weapon in the full version of Crackdown 2, due out in July.
This isn't the first time Microsoft has linked an Xbox Live with a Facebook game promotion. Back in March, they launched a Match Defense game in conjunction with Xbox Live Arcade release Toy Soldiers.
We're 99% sure Chuck's Ducks 1 doesn't actually exist.