Here is the full list of all 24 Auto Cast achievements.
Kill your first boss
Level an ability to level 6
Unlock the final talent
Max out gold gain in the shop
Collect 100 gold
Successfully complete 20 monuments
Reject 20 monuments
Equip an item 50 times
Max 3 different abilities in a single run
Deal 500 damage with the Toadstool’s gas
Have max armor and 150 health or more in a single run
Become engulfed by darkness 30 times
Activate The Escape plan 20 times
Slow an enemy 200 times with Inhibitors Eye or Elusive Nature
Discard 100 items
Replace 75 items
Kill 20,000 enemies
Start 10 runs
Be offered 25 chest from the Chest Giver
Hit 100 trees, bushes, or rocks
Kill the final boss 5 times
Reach prestige 20
Charge 20 relic charges
Die to a trap