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