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