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