There is a secret area in Geometry Dash called "The Basement." It holds a prisoner called the Demon Guardian. You can free him to unlock the Demon Gauntlet, icons, and other rewards.

In order to unlock the basement and free the demon guardian, you need to:

• Collect 50 diamonds
• Use code "The Challenge" in the Vault of Secrets
• Collect 200 total diamonds
• Beat The Challenge
• Press the door in the bottom right to unlock the basement
• Press the 3 key slots
• Collect 500 total diamonds
• Buy the "Master Emblem" from the secret shop
• Open the treasure chest in the Chamber of Time to get the first basement key
• Collect 50 demon keys and open 50 demon chests in the Treasure Room
• Open the available special demon chest to get the second basement key
• Complete the Chaos Gauntlet to get the third basement key
• Press the 3 key slots again

Upon completing the above, you will unlock the basement and free the demon guardian. This will unlock the Demon Gauntlet, some icons, and other rewards.

Here are some more in-depth instructions:

• Unlocking "The Challenge"
• Unlocking the "Chamber of Time" (First Key)
• Opening 50 demon chests (Second Key)
• Completing the Chaos Gauntlet (Third Key)

Unlocking "The Challenge"

To unlock the challenge, you need 200 total diamonds. Follow these instructions to unlock the Vault of Secrets, which you need to unlock The Challenge

If you need help collecting diamonds, here are some tips for collecting diamonds easily.

This will unlock the basement.

Unlocking the "Chamber of Time" (First Key)

To unlock the Chamber of Time, you need to buy the Master Emblem from the secret shop. Follow these instructions to buy the Master Emblem and unlock the Chamber of Time.

If you need help unlocking the secret shop, follow these instructions to unlock the secret shop.

This will reward you the first basement key.

Opening 50 Demon Chests (Second Key)

You need 50 demon keys to open 50 demon chests. Follow these instructions to unlock the Treasure Room, which you need to open 50 demon chests.

If you need help collecting demon keys, here are some tips for collecting demon keys easily.

This will reward you the second basement key.

Completing the Chaos Gauntlet (Third Key)

The Chaos Gauntlet is a difficult Gauntlet to beat, but with this guide, it can be made a lot easier. You don't need to do anything prior to unlock the Gauntlet. Simply complete the Chaos Gauntlet.

This will reward you the third basement key.

And there you go! If you need additional help unlocking the basement and freeing the Demon Guardian, we have an even more in-depth, step-by-step tutorial you can see.