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