Here is the full list of all 13 DIVE Greybox Demo achievements.
Collect all health upgrades.
Collect all stamina upgrades.
Collect all flask upgrades.
Defeat the Rock Anomaly.
Defeat the Rock Anomaly without taking damage.
Defeat the chamber guardian Phalanx.
Defeat the chamber guardian Phalanx without taking damage.
Acquire the starting pod.
Complete the demo chambers.
Complete the demo puzzles.
Find the crown.
Defeat Phalanx within 25 minutes of starting the demo.
Defeat Phalanx within 15 minutes of starting the demo.