Full list of all 23 Going Under achievements worth 1,050 gamerscore. It takes around 12-15 hours to unlock all of the achievements in the base game on Xbox One.
The base game contains 20 achievements worth 1,000 Gamerscore, and there is 1 DLC pack containing 3 achievements worth 50 Gamerscore.
Unlock all skills.
Kill a power loader with Exit Strategist
Save the World?
Defeat Vested Marv.
Obtain Hover Hands' Share.
Kill a Hungry Box.
Obtain Hustlebones' Share.
Obtain The Caffiend's Share.
Go Under.
Complete Fern's mentorship.
Complete Swomp's mentorship.
Complete Tappi's mentorship.
Complete Kara's mentorship.
Get cursed 13 times.
Complete Ray's mentorship.
Open 100 delivery cubes.
Obtain The Toxic Mask.
Obtain The Grim Ledger.
Obtain The Mana Press.
Meet Your Coworkers.
Win a run in Impostor Mode.
Complete the Rolodex
Complete The Impostor's final test.