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