Here is the full list of all 35 Avernum: Escape From the Pit achievements.
Get a dread curse. Then cure it.
Have ten potions made.
Find the secret at the bottom of Lost Bahssikava.
Dig up 5 caches.
Avernum has five dragons. See if you can whittle that down a bit.
Learn 6 mage spells at level 3.
Steal the treasure from Gremlin's Gold.
Learn 6 priest spells at level 3.
Sss-Thsss will trouble Avernum no longer.
Purge a certain powerful demon from the Tower of Magi. Phew. Hope they stay out of trouble in the future.
Meet the Archmage Erika.
Learn a mage spell at level 3.
Slay 1000 foes.
Discover 50 locations of interest.
Learn a priest spell at level 3.
Join the Scimitar.
Enter the Castle at last.
Discover 10 locations of interest.
The mayor of Formello lost something of great value. Recover it.
Open a secret door.
Slay 100 foes.
Purge a nefarious infiltrator from Silvar's sewers.
Escape the tunnels under Fort Avernum.
Learn 18 mage spells at level 3.
Learn 18 priest spells at level 3.
Dig up 40 caches.
Have fifty potions made.
Find something that lets you fly.
Reform a legendary blade from Avernum's past.
Destroy the demon Grah-Hoth, making Avernum safe from his menace at last.
Discover a route back to the surface world. There must be one somewhere.
Deliver harsh vengeance to the cruel tyrant who sent the Avernites into the underworld.
Complete all three game-winning quests in Avernum and never set the difficulty below Normal.
Complete all three game-winning quests in Avernum and never set the difficulty below Hard.
Complete all three game-winning quests in Avernum and never set the difficulty below Torment.