They can be selected, which will destroy them. The level and references to it throughout the game were removed from the code in subsequent versions. It was still present after Update 1.5, being updated to reward 13 stars.
It would have been an Insane difficulty level rewarding 12 stars. A level named Active (music by DJVI) was seemingly planned for after Update 1.4, where the incomplete level was present in the game's code.
Theory of Everything 2 (20 secret coin lock)
