Here is the full list of all 11 Lost Meridian achievements.
Kill Dungeon I boss Lord Faragon
Kill Act 1 Boss Entleaf
Kill Act 2 Boss Lava Dragon
Kill Dungeon 2 Boss Avatar of Pain
Complete the game on easy difficulty
Win a battle
Upgrade a card
Deal over 200 damage in a single attack
Complete the game on normal difficulty
Complete the game on hard difficulty
Complete the game on brutal difficulty