Here is the full list of all 119 Torchlight II achievements. It takes around 200 hours to unlock all of the achievements on Windows.
Use an enchanter 500 times
Fish 1,000 times
Have 10,000,000 gold
Sell 50,000 items
Use 5,000 potions
Deal 100,000 critical strikes
Destroy 100 socketed gems
Begin new game plus
Defeat the Nether King with each of the 4 classes
Defeat the Nether King in Elite difficulty
Defeat the Nether King as an Engineer
Defeat the Nether King in hardcore mode (casual)
Defeat the Nether King in hardcore mode (elite)
Defeat the Nether King in hardcore mode (normal)
Defeat the Nether King in hardcore mode (veteran)
Use 100 maps
Defeat the Nether King as a Berserker
Defeat the Nether King in Veteran difficulty
Socket 500 gems into items
Reach level 100
Obtain a tier 3 skill bonus
Break 10,000 breakables
Have 50 friends
Have 1,000,000 gold
Find 100 secret rooms
Defeat the Nether King as an Embermage
Sell 5,000 items
Have 10 friends
Add a friend
Defeat 500 champions
Purchase 100 items from the gambler
Find a legendary item
Use an enchanter 50 times
Destroy 10 socketed gems
Start a multiplayer game
Use 10 maps
Use 500 potions
Have 100,000 gold
Recover 100 gems from items
Explode 10,000 enemies
Use a map
Defeat the Nether King in Casual difficulty
Defeat the Nether King in Normal difficulty
Defeat the Nether King as an Outlander
Defeat the Nether King
Defeat the Dark Alchemist
Defeat Verona
Defeat Aleera
Deal 10,000 critical strikes
Defeat Marishka
Assemble TrillBot
Defeat Killbot
Defeat Vyrax
Do 10,000 damage with a single attack
Socket 50 gems into items
Defeat Thiss
Find 10 secret rooms
Squish 1000 critters
Use an enchanter 10 times
Defeat Cacklespit
Die with a hardcore character
Defeat Bloatfang
Defeat the Grizzled Alpha
Take 100,000 steps
Purchase 50 items from the gambler
Obtain a tier 2 skill bonus
Defeat the Wraith Lord
Defeat Boletus Rex
Defeat the Siege Guardian
Defeat Ezrek Khan
Defeat the King In Masks
Squish 500 critters
Defeat Aruk
Destroy a socketed gem
Defeat the Artificer
Purchase 20 items from the gambler
Recover 10 gems from items
Open 500 chests
Teach a pet 4 spells
Defeat the Manticore's Mate
Defeat the Manticore
Start a hardcore character
Defeat 100 champions
Break 1,000 breakables
Learn 4 spells
Take 50,000 steps
Wear a completed armor set
Defeat Grand Regent Eldrayn
Deal 1,000 critical strikes
Defeat King Pogg
Sell 500 items
Trade an item with another player
Join a multiplayer game
Fish 100 times
Recover a gem from an item
Defeat Chillhoof
Use 50 potions
Defeat Kidrik the Mauler
Teach a pet a spell
Learn a spell
Defeat the Winter Widow
Defeat 25 champions
Explode 1,000 enemies
Defeat General Grell
Squish 100 critters
Find a secret room
Obtain a tier 1 skill bonus
Defeat One-Eyed Willy
Defeat Mordrox
Open 100 chests
Take 10,000 steps
Fish using dynamite
Socket a gem into an item
Break 100 breakables
Defeat the Fallen Guardian
Send your pet to town
Explode 100 enemies
Open 20 chests
Fish 10 times