Well, I have plenty to report:
Firstly, I took a picture of the opening screen and each level. The game opens up in the exact same fashion as the "Off the Wall" prototype does. The player is greeted with "Tengen presents: Debug Level II."
After a bit messing around, I discovered an insanely awesome debug menu. I have pictures of each "Test" that will likely do more justice than my simple explanation would. Each test has to do with sound effect and things of that nature, but one choice allows you to mess with the color pallet. At the end of all the test, the game defaults to a debug mode that allows you to "fly" your Marble across each landscape. The color of the level depends on the pallet you chose. I'm sure this sounds insanely confusing, but the pictures will help put things together.
As an aside, the second Marble is pictured leading me to believe this is a legitimate two player game.
I'm putting some primitive watermarks on the pictures and plan on uploading them shortly.