Full list of all 21 Magic: The Gathering - Duels of the Planeswalkers achievements worth 350 gamerscore.
The base game contains 12 achievements worth 200 Gamerscore, and there are 3 DLC packs containing 9 achievements worth 150 Gamerscore.
Defeated someone who has earned the Spellslinger achievement
Won 10 Xbox LIVE matches
Won 5 ranked Xbox LIVE matches
Unlocked 100%
Defeated Tezzeret the Seeker & Sarkan Vol in the cooperative campaign
Won a Two-Headed Giant game
Completed all challenges
Completed a challenge
Defeated Tezzeret in the final single-player campaign battle
Increased your life total to 30 or more in single player, or 60 or more in Two-Headed Giant
Dealt 20 combat damage to a player in a single turn in a game
Won a game
Controlled creatures with a total power of 75 or more (Expansion Pack 1)
Earned Puzzling Master and completed all Expansion 1 challenges
Defeated Nicol Bolas in the single player campaign (Expansion Pack 1)
Won a 3- or 4-player Xbox LIVE match (Expansion 2)
Defeated Sorin Markov in the single-player campaign (Expansion 2)
Put 8 lands onto the battlefield in one turn (Expansion 2)
Dealt 12 combat damage to an opponent in a single attack with one blue creature (Expansion 3)
Defeated Sarkhan the Mad in the single-player campaign (Expansion 3)
An opponent's last permanent left the battlefield (Expansion 3)