Tengoku & Jigoku

Simulator in progress, here is the game structure:



Manual is fully scanned already.

A preview version should be released shortly.

Mystery?

I've seen some early photos of some of the Japanese Bandai solar games that have never actually been released! Are they prototypes? Here are some pictures:

A small version of Daidassou (never released in that format!):



A small version of Nazo No Chinbotsusen (never released in that format!):



A small version of Gekisen U-Boat (released in that format outside Japan as Sub Attack, Sub Patrol and U-Boat):



A small version of Kyofu No Mujintou (release in that format outside Japan as Shark Island):



On the other hand I have not seen any trace of an existing large version of Tengoku & Jigoku (Escape from the Devil's Doom)...

If anyone has any information I would be very interested.

Links:
- Missing versions?