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