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