Here is the full list of all 20 Chasm achievements. It takes around 20-25 hours to unlock all of the achievements on Windows.
Defeat a boss without getting hit.
Explore 100% of the map.
Complete all villager sidequests.
Find all the Journal Entries in the game.
Complete the game on Hard difficulty.
Complete the game as a Mortal.
Unlock all the Bestiary entries.
Spend 5,000 gold.
Defeat Ulak.
Break all the crates in the game.
Defeat the Shaman.
Find all the Powerups in the game.
Defeat 1,000 enemies.
Rescue all the missing villagers.
Defeat King Trell.
Become the Arena champion.
Defeat the Titan.
Defeat the Bone Worm.
Defeat the Wendigo.
Defeat 100 enemies.