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
Acquire 20 traits
Acquire 10 Relics
Craft 15 Weapon Mods
Acquire 30 Guns
Defeat the Fae Imposter
Acquire 20 Melee Weapons
Acquire the Max Number of Trait Points
Acquire 10 Melee Weapons
Acquire 100,000 Scrap
Listen to All of Mudtooth's Stories
Discover a Blood Moon Room
Meet the Custodian
Defeat Guardian of N'Erud
Defeat the Final Boss
Discover Leto's Stash
Acquire 15 Guns
Defeat 25 Aberrations
Upgrade a Boss Weapon to +10
Receive an Alignment Reading from Meidra
Upgrade a Standard Weapon to +20
Obtain 10 Traits
Meet Nimue
Acquire 50,000 Scrap
Reach Level 10 on Any Archetype
Craft an Item at the Blood Moon Altar
Upgrade a Weapon Mutator to +10
Defeat Many Faces
Defeat 10 Aberrations
Obtain a Secret Archetype
Acquire a World Boss's Alternate Reward
Defeat Tal'Ratha
Upgrade a Standard Weapon to +10
Defeat 100 Special Enemies
Defeat the Nightweaver
Obtain an Item From the Nightweaver's Web
Craft a Non-Starter Weapon Mod
Upgrade a Boss Weapon to +5
Craft a Boss Weapon
Upgrade Relic Capacity
Upgrade Any Trait to 10
Defeat the Labyrinth Boss
Defeat the Ravager
Defeat a World Boss
Play a Secret Song on the Water Harp
Slot a Second Archetype
Meet the Flautist
Obtain a Non-Starter Trait
Choose Your First Archetype
Defeat the Root Mantis