Here is the full list of all 100 Spirit Hunters: Infinite Horde achievements.
Win 3 Sickle Challenges
Win 3 McDiggins Challenges
The Twilight Oasis boss Oniclaw was defeated
Have 5 max level pets in a run
The Desert Ruins boss Horned Beetle was defeated
The Spine Dunes boss Tempest was defeated
The Hinterlands boss Horse Knight was defeated
The Viper Village boss Viper Shaman was defeated
The Northwood boss Yak Colossus was defeated
The Darkmoon Grove boss Tombstone was defeated
The Cemetery Boss Demise was defeated
Win 3 Shakpana Challenges
Win 3 Hugo Challenges
20 total challenges
Win 3 Maxine Challenges
Win 3 Conrad Challenges
Twilight Oasis brutal challenge unlocked
Twilight Oasis Skull 2 challenge unlocked
10 total challenges
Win 3 Vivian Challenges
5 total challenges
Win 3 Magnus Challenges
The Lunar Caverns battle is now unlocked
The Twilight Oasis Battle is now unlocked in the Desert
Unlocked the Hero Sickle
Unlocked the Hero McDiggins
1 Ledger challenge
The Jinn ability was unlocked
The Shock Bolt ability was unlocked
The pet Blocker unlocked and obtainable in battle
Spine Dunes brutal challenge unlocked
Northwood brutal challenge unlocked
The Cemetery brutal challenge unlocked
The Hinterlands brutal challenge unlocked
Viper Village brutal challenge unlocked
Darkmoon Grove brutal challenge unlocked
The pet Trove unlocked and obtainable in battle
The pet Pack Rat unlocked and obtainable in battle
The pet Webster unlocked and obtainable in battle
Desert Ruins brutal challenge unlocked
Purchased 400 upgrades in the Divinity Web
Northwood Skull 2 challenge unlocked
The Northwood Battle is now unlocked in the Highlands
The Poison Cloud ability was unlocked
Unlocked the Hero Shakpana
Hardcore mode unlocked
Purchased 350 upgrades in the Divinity Web
Spine Dunes Skull 2 challenge unlocked
The pet Big Tex unlocked and obtainable in battle
The pet Nomicron unlocked and obtainable in battle
Darkmoon Grove Skull 2 challenge unlocked
Purchased 300 upgrades in the Divinity Web
The Cemetery Skull 2 challenge unlocked
Viper Village Skull 2 challenge unlocked
The pet Crys unlocked and obtainable in battle
Purchased 250 upgrades in the Divinity Web
The Cemetery battle is now unlocked in the Dark Forest
The pet Madrake unlocked and obtainable in battle
Purchased 200 upgrades in the Divinity Web
The pet WhooDoo unlocked and obtainable in battle
The pet Beacon unlocked and obtainable in battle
The Hinterlands Skull 2 challenge unlocked
Purchased 150 upgrades in the Divinity Web
The Shadow Shuriken ability was unlocked
The Viper Village battle is now unlocked in the Highlands
Purchased 125 upgrades in the Divinity Web
The pet CiCi unlocked and obtainable in battle
The Bone Shot ability was unlocked
The Spine Dunes battle is now unlocked in the Desert
The Darkmoon Grove battle is now unlocked in the Dark Forest
Purchased 100 upgrades in the Divinity Web
Unlocked the hero Hugo
The Magic Mine ability was unlocked
The pet Rupert unlocked and obtainable in battle
Purchased 75 upgrades in the Divinity Web
The pet Hearty unlocked and obtainable in battle
Unlocked the hero Maxine
The Grand Hex ability was unlocked
The pet Chicon Rad unlocked and obtainable in battle
Purchased 50 upgrades in the Divinity Web
The pet Lock Pick unlocked and obtainable in battle
Purchased 40 upgrades in the Divinity Web
Purchased 30 upgrades in the Divinity Web
Unlocked the hero Conrad
The Tangle Vines ability was unlocked
Desert Ruins Skull 2 challenge unlocked
The Tornado ability was unlocked
Purchased 20 upgrades in the Divinity Web
The Hinterlands battle is now unlocked in the Highlands
Purchased 10 upgrades in the Divinity Web
Purchased 5 upgrades in the Divinity Web
Pets unlocked on the battlefield. Unlocked Slayther, Driller, MagSlime, Flash and Scoop
Lunar Caverns hard challenge unlocked
Lunar Caverns brutal challenge unlocked
Win 1 challenge with each hero
30 total challenges
The Lunar Caverns boss Megnacrom was defeated
Ultimate power reached! Obliterate the Horde!
Have 20,000 gold in a run
Defeat all 27 bosses