In this video, I'm showing you how to unlock Demon Gauntlet, and how to unlock the 3 keys on the door in Vault of Secrets.
How to open the door in Vault of Secrets | Geometry Dash
https://youtu.be/rQ_ivQqXiW0
How to unlock Chamber of Time | Geometry Dash
https://youtu.be/1AKtKkeK8F4