Here is the full list of all 66 Torchlight achievements. It takes around 100-120 hours to unlock all of the achievements on Windows.
Die 500 times
Sell 10,000 items to vendors
1 game mod installed
5 mods installed at the same time
10 mods used at the same time
Catch 1000 fish
Achieved enlightenment by speaking with the horse 100 times
Defeat Ordrak on Hard Hardcore
Drink 5,000 potions
Defeat Ordrak on Easy Hardcore
Complete 50 Hatch Quests
Retire over 300 levels worth of characters
Defeat Ordrak on Very Hard Hardcore
Defeat Ordrak on Normal Hardcore
Defeat Ordrak on Very Hard
Kill 25 champion trolls
Gamble 100 times
Defeat Ordrak in 8 hours or less
Defeat Ordrak in less than 5 hours
Kill 50,000 monsters
Suffer 20 disenchants from the enchanter
Defeat Ordrak with no deaths
Beat the game with all three classes
Retire two characters
Defeat Ordrak on Hard
Catch 100 fish
Complete 200 Quests
Gamble 50 times
Retire a character
Transform your pet into a Mimic
Gamble a unique item
Gamble 20 times
Permanently transform your pet
Reach level 100
Successfully enchant one item 10 times
Achieve player level 100
Reach the 50th floor of a dungeon
Use 50 potions on your pet
Achieve maximum fame
Smash 1500 Breakables
Do at least 10,000 damage to an enemy in a single strike
Complete 25 Gar Quests
Achieve player level 65
Catch 50 fish
Successfully enchant one item 5 times
Have an item disenchanted on the first enchantment attempt
Collect 250,000 gold
Defeat Ordrak on Easy or Normal
Defeat Alric
Change your pet by feeding it fish
Defeat Medea
Have 100,000 gold in your inventory
Defeat Krag
Take 25,000 steps
Kill 5000 Monsters
Defeat the Ember Colossus
Equip a spell on your pet
Pull 100 levers
Defeat the Root Golem
Successfully create 25 items using the transmuter
Defeat the Overseer
Fill your pet's inventory
Defeat Brink
Blow 25 enemies to pieces with critical strikes
Send your pet to town
Find the entrance to the mine