Here is the full list of all 53 Puzzle Quest 2 achievements.
Complete the game
Gain access to Gorgons Cathedral
Escape the Dark Dwarven Laboratory
Defeat the monster known as "Teh SkullBrekker"
Do more than 250 damage during your turn
Complete the "Able Replacement" quest
Forge the "Hammer of Righteousness"
Magically force your way through 5 locks
Disarm 5 traps to avoid being wounded
Defeat Shadowbringer
Upgrade an item to Epic
Search 5 rooms for hidden treasure or danger
Defeat King Godd
Bash your way through 5 locks
Defeat the Yeti
Upgrade an item
Complete the "Stuff of Nightmares" quest
Defeat an opponent while on 1 Life Point during any single player game mode
Clear the town of Goblins.
Defeat an opponent on your first turn during any single player game mode
Be defeated by an opponent on their first turn during single player quest mode
Lose to an opponent who's on 1 Life Point during any single player game mode
Make a match of 8 gems in a row in any battle game mode
Learn all the bonus spells
Defeat 500 monsters
Defeat the Green Dragon
Choose the Bash mini-game whenever possible during the single player campaign
Win 5 Tournaments
Survive the Endurance mode
Defeat 5 opponents in multiplayer
Respec your hero by visiting Jarrum Blackstone in the Chapel
Heal some trap damage by visiting Jarrum Blackstone in the Chapel
Pick your way through 5 locks
Defeat 1000 monsters
Defeat 2000 monsters
Finish the single player campaign with a hero from each class
Finish the single player campaign with both male and female from the one class
Watch the credits sequence to the end
Play the "Lucky Dip" side quest
Visit every room in the game
Complete the game without activating an item
Advance to the Green Dragon in Endurance mode on full health
Resist Subjugate or Crushing Kill
Win a Tournament with the first or second hero alive
Activate 5 traps during a campaign
Kill an undead monster, then kill it again and again after it reanimates
Lose the burning inn challenge battle
Defeat a Yeti after at least 100 turns have passed
Complete the "Eye of the Owlbear" quest
Defeat the Arch Lich
Complete the "Imp!" quest for Crye
Complete the "Insurance Fraud" quest
Complete the "Deep Delving Dwarf" quest