Why this page exists: A player wants to understand which progression systems are documented before chasing a hidden trigger.
Four progression buckets
Treat difficulty access, zookeeper unlocks, challenge access, and achievements as separate systems. The launch post gives counts and explains challenge points, but it does not map every locked collection item to a trigger.
- Challenge locked → five of 24 start open; wins award challenge points, with higher difficulties awarding up to eight.
- Difficulty locked → on v1.0.2 or later, a higher-difficulty trigger should also grant the lower difficulties.
- Zookeeper locked → 20 are named as launch content, but the reviewed first-party sources do not map each keeper to a trigger.
- Achievement locked → treat it as a separate version-sensitive problem and use the achievement-fix guide before assuming progression is blocked.
The v1.0.2 difficulty change
The official patch says a difficulty unlock trigger now activates all lower difficulties too. That is useful when a higher-difficulty run previously left a lower reward locked.
The note does not identify every reward affected, so it should not be expanded into a complete checklist without an in-game collection audit.
Where this guide stops
No complete first-party table of zookeeper, mode, animal, snack, souvenir, and special-event triggers was located. Pages that claim one should show a current build and direct evidence for every row.