Full list of all 96 UnderMine achievements.
The base game contains 94 achievements, and there is 1 DLC pack containing 2 achievements.
Discovered the Golden Idol
Completed 3 runs of Othermine without dying
Entered the Golden Core before defeating Ponzu
Lifted the Summoning Stone 10 times
Completed a run of the Othermine
Died 50 times
Rescued Kurtz
Defeated Selt, Lord of Sand without upgrades
Learned 10 new blessings
Defeated Seer, World's Heart
Transmuted 3 Relics at the same time using Transmutagen
Discovered the Othermine
Entered the Golden Core
Crafted 20 new relics
Crafted 30 new relics
Found all 3 dogs in the UnderMine
Crafted 10 new potions
Fully upgraded the bombs
Fully upgraded the gloves
Fully upgraded the tunic
Completely expanded the Pilfer shop
Peeped 100 skeletons
Thwarted 500 pilfers
Fully upgraded the pickaxe
Lost 5,000 gold to pilfers
Spent 100,000 gold at shops
Held 3 of the same potion at the same time
Fully upgraded the goldsack
Held 99 keys at once
Bought every item in a fully expanded shop
Fully expanded the potion slots
Defeated Selt, Mortar, and Noori with the same peasant
Held 99 bombs at once
Crafted a new potion
Lifted the Summoning Stone for the first time
Defeated Ponzu, Scaled Assembly
Completely expanded Dibble's shop
Spent 50,000 gold at shops
Learned a new blessing
Fully upgraded the counter weight
Defeated a Hoarding Pilfer
Crafted 10 new relics
Stole an item from the shop
Expanded the potion slot once
Entered the Shimmering Caverns
Defeated Noori, Spectre of Darkness
Spent 10,000 gold at shops
Assisted Beltrame
Had 6 curses active at the same time
Ate cooked food for the first time
Defeated Mortar, Charged Golem
Healed 1,000 hp using food in one run
Had something popcorn 5 times in a row
Died 10 times
Rescued Lillyth
Defeated the Dungeon Gargoyles
Joined the Pilfer Loyalty Program
Entered the Halls of Din
Entered the Halls of Din before defeating Mortar
Put yourself out in water
Rescued Dibble
Peeped 10 skeletons
Crafted a new relic
Destroyed 20 signs
Entered the Delvemore Dungeon
Defeated Selt, Lord of Sand
Discovered a secret floor
Cleansed a curse for the first time
Met Black Rabbit
Rescued Dodson
Discovered a secret room
Defeated the Rockpile Mimic
Rescued Wayland
Entered the Delvemore Dungeon before defeating Selt
Died 100 times
Died with an Elixir in your inventory
Spawned a secret shop, in a secret shop, in a secret shop
Defeated Noori, Spectre of Darkness without upgrades
Defeated Mortar, Charged Golem without upgrades
Defeated Ponzu, Scaled Assembly without upgrades
Lifted the Summoning Stone 30 times
Completed an Othermine run without upgrades from the antechamber chest or shops
Defeated Seer, World's Heart without upgrades
Completed a run with at least 2 hexes