Full list of all 41 Castle of no Escape 2 achievements worth 5,000 gamerscore. It takes around 0-0.5 hours to unlock all of the achievements in the base game.
The base game contains 21 achievements worth 1,000 Gamerscore, and there are 4 DLC packs containing 20 achievements worth 4,000 Gamerscore.
Watch 100 enemies die from traps
Don't use the crystal orbs
Always leave any room in 30 seconds
Complete the game as a guardian
Complete the game as a huntress
Exactly this
Collect 10,000 gold
Upgrade an armor with emblems
Watch 50 enemies die from traps
Don't pick up a shield
Complete the game as a cardinal
Play more than 10 hours
Complete the game with no damage
Don't kill any monsters (including the fallen hero)
Don't pick up an armor
Complete the game as a shamaness
Collect the false sword
Complete the game as a bandit
Complete the game as a champion
Collect all the gems and a sword, then use an orb
Allow the phantom to steal 10,000 gold
Kill 15 enemies
Collect 200 coins
Kill 10 enemies
Visit 15 rooms during one run
Visit 12 rooms during one run
Reach the fifth floor of the castle
Reach the fourth floor of the castle
Reach the third floor of the castle
Reach the sixth floor of the castle
Reach the second floor of the castle
Die within the walls of the castle
Explore 6 rooms of the castle
Explore 3 rooms of the castle
Return to the start room
Use the ritual from the menu
Explore 30 rooms
Explore 20 rooms
Explore 50 rooms
Explore 40 rooms
Explore 10 rooms