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