Full list of all 60 Remnant II achievements. It takes around 60-80 hours to unlock all of the achievements in the base game on Windows.
The base game contains 50 achievements, and there are 2 DLC packs containing 10 achievements.
Defeat a Boss in Single-Player Without Taking Any Damage
Defeat 25 Aberrations
Defeat Many Faces
Discover a Blood Moon Room
Discover Leto's Stash
Acquire 20 traits
Craft an Item at the Blood Moon Altar
Acquire 30 Guns
Acquire 20 Melee Weapons
Acquire 10 Relics
Defeat Tal'Ratha
Craft 15 Weapon Mods
Acquire 10 Melee Weapons
Upgrade a Boss Weapon to +10
Acquire a World Boss's Alternate Reward
Defeat the Ravager
Play a Secret Song on the Water Harp
Defeat 10 Aberrations
Defeat the Fae Imposter
Receive an Alignment Reading from Meidra
Acquire 15 Guns
Upgrade a Weapon Mutator to +10
Acquire the Max Number of Trait Points
Acquire 100,000 Scrap
Meet Nimue
Defeat the Labyrinth Boss
Defeat Guardian of N'Erud
Upgrade a Standard Weapon to +20
Acquire 50,000 Scrap
Obtain 10 Traits
Defeat the Final Boss
Listen to All of Mudtooth's Stories
Defeat 100 Special Enemies
Meet the Flautist
Upgrade a Boss Weapon to +5
Craft a Boss Weapon
Defeat the Nightweaver
Defeat a World Boss
Obtain an Item From the Nightweaver's Web
Upgrade a Standard Weapon to +10
Slot a Second Archetype
Obtain a Secret Archetype
Upgrade Relic Capacity
Craft a Non-Starter Weapon Mod
Reach Level 10 on Any Archetype
Obtain a Non-Starter Trait
Upgrade Any Trait to 10
Meet the Custodian
Choose Your First Archetype
Defeat the Root Mantis