Brick walls (Main Menu)

''This article is about the covering in the Main Menu. For the obstacle, see Brick walls (obstacle).''

When a level has not yet been unlocked, a brick wall covers it. The player cannot see the content of the level unless they unlock it the next time they play.

Unlocked Checkpoint Glitch
In the Random Rooms Glitch, the rooms are randomly shuffled. If the player reaches a room where its checkpoint has not been unlocked, then the brick wall will be removed, but the level cannot be accessed, only seen (only unlocked upon reaching a certain distance.). It is called the Unlocked Checkpoint Glitch.