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