Here is the full list of all 26 Delver achievements.
Max out on backpack slots.
Listened to the wise.
Max out on belt slots.
Chow down on 40 things in one run.
Bought something from the wizard.
Find 300 gold in one run.
Use 15 potions in one run.
Take 400 damage in one run.
Use 10 scrolls in one run.
Zap wands 300 times in one run.
Become poisoned 10 times in a run.
Trip 10 traps in one run.
Buy a magical elixer from Joff.
Identify 5 items in a run.
Find 5 secret areas in one run.
Escaped with the Orb.
Grab the orb.
Buy a belt slot.
Buy a backpack slot.
Bought something from Joff.
Died, for the first time.
Make it through the Ruins
Make it through the Sewers
Kill 150 monsters in one run.
Make it through the Caves
Make it through the Dungeons