Big Goodbye Hidden Achievement

The useful answer

Requirement: finish the standard ending. Complete the main colored-tower progression and follow the ending route.

Official Big Walk screenshot showing players stacking and gesturing together on the beach at sunset. The guide below explains the relevant route, item or multiplayer behavior.Official screenshot © House House / Panic

Step by step

Complete the main colored-tower progression and follow the ending route.
Wait for the achievement notification before leaving the area.
If it does not unlock, let the host save, regroup and repeat the final interaction.

Why players get stuck here

Steam has 12 in-game achievements. PS5 uses the same 12 requirements and adds Big Trophy, the platinum awarded after the others. Progression achievements are easiest with the same host because the host owns the world save.

Quick checklist

Required action: finish the standard ending
Use the same host for progression
Keep the game version matched across the group
Check the full 100% list before final cleanup

Verify it before moving on

Wait for the platform notification before marking the requirement complete. If it does not appear, keep the same host, reload the saved world and repeat only the final trigger instead of restarting the whole route.

Sources checked

Printable PS5 trophy list — official names and descriptions
Big Walk community guide index — completion route cross-check