Full list of all 25 Castle of no Escape achievements worth 4,000 gamerscore. It takes around 0-0.5 hours to unlock all of the achievements in the base game.
The base game contains 10 achievements worth 1,000 Gamerscore, and there are 3 DLC packs containing 15 achievements worth 3,000 Gamerscore.
Complete the game as a shamaness
Complete the game as a champion
Don't kill any monsters (except the boss)
Don't use the crystal orbs
Complete the game with no damage from enemies
Complete the game as a bandit
Collect all the gems, then use an orb
Get damaged by explosive chest
Pick up a weapon
Pick up an armor
Reach the 4th floor
Reach the 5th floor
Reach the 3rd floor
Reach the 6th floor
Reach the 2nd floor
Drink from the pool
Read the book
Find some flares
Find some gold in the chest
Find some gold
Visit every space on a floor
Kill every enemy on a floor
Use a flare when you're forgetful or blind
Fall in the hole
Select a secret character