Here is the full list of all 38 Returnal achievements. It takes around 40-50 hours to unlock all of the achievements on Windows.
Finish Crimson Wastes Survey
Finish Abyssal Scar Survey
Complete a daily challenge in Simulation Mode
Collect all main Achievements
Kill 100 Hostiles with Disgorgers
Gain a moment of peace
Finish Fractured Wastes Survey
Finish Derelict Citadel Survey
Finish Overgrown Ruins Survey
Open the Locked Door
Finish Act 3
Have 5 Parasites simultaneously
Finish Echoing Ruins Survey
Complete all House sequences
Defeat Algos' final form
Achieve Weapon Proficiency level 30
Finish Act 2
Defeat Ophion
Defeat Hyperion
Finish Act 1
Defeat Nemesis
Achieve 200% Max Integrity
Finish Calculated Risk
Complete a Xeno-archive set (excluding Tower of Sisyphus)
Unlock all translation tiers of a Xenoglyph
Complete the first Hospital sequence
Die and return in the Tower
Defeat Algos' first form
Defeat Ixion
Retrieve 10 Scout Logs
Defeat Phrike
Perform 5 successful Overloads in a row
Scan a Xenoglyph
Returned by an Artifact
Learn the basics of survival on Atropos
Complete the first House sequence
Achieve maximum Adrenaline Level
Experience a new cycle after death