Full list of all 15 Magic: The Gathering - Duels of the Planeswalkers 2012 achievements worth 250 gamerscore.
The base game contains 12 achievements worth 200 Gamerscore, and there is 1 DLC pack containing 3 achievements worth 50 Gamerscore.
Completed the Archenemy campaign
Solved Fifteen Challenges
Defeated an Archenemy in a game
Defeated Karn in a campaign game
Defeated Gideon in the Single-Player Campaign
Defeated Chandra in the Single-Player Campaign
Defeated Kiora in the Single-Player Campaign
Controlled three artifacts in a game
Cast a Mythic rare spell in a game
Solved a Challenge
Defeated Koth in the Single-Player Campaign
Hosted an Archenemy match on Xbox LIVE with two human teammates
Defeated Jace, Jace and Jace as the Archenemy in a campaign game
Defeated Gideon, Garruk and Koth as the Archenemy in a campaign game
Hosted a match on Xbox LIVE as the Archenemy