Here is the full list of all 24 God Mode achievements.
Complete all maps on hardest difficulty
Collect 5 000 000 unspent gold
Kill 25 000 creatures
Kill 2500 creatures
Survive the "Death" Test of Faith
Complete any map on Platinum difficulty
Reach the final level and attain God Mode
Destroy 50 scarab eggs before they hatch
Purchase all upgrades
Purchase your first weapon upgrade
Finish any map with 3 or more active Oaths
Finish any map with 6 active Oaths on hardest difficulty
Decapitate 100 Skeletons
Buy Super Pants
Complete any map without dying
Trigger 20 Mage seals
Kill 100 creatures
Grind 50 creatures using the Buzzsaw melee attack
Kill 50 enemies using melee
Fully upgrade one weapon
Kill 20 creatures using the Hammer ability
Complete your first Oath
Finish any map on any difficulty
Enrage 10 Cyclops