I don't think there were any gameplay changes between the eu/us/jpn versions throughout the whole series, the only one I know about was that that the level select/secret minigame codes didn't work in the US version of Keio 1.
But what's the difference between the different Japanese Saturn versions?
And is the PSX version different?
Keio Yuugekitai Okiraku Tamatebako is a demo/bonus CD which included the videos of the 2 eps (the Mega CD videos were of course higher quality), a dozen or more artwork pics, and demo stages for Keio Yuugekitai (keio FS 2), one for the platform and one for the shooting levels.
The platform level was just the first stage of KFS2 (though a few minor things were different in it), the shooting stage is... I got no clue wtf it actually is. Imagine it like BGs and enemy sprites being drawn by a 5 year old, and I believe the boss was a giant kangaroo shooting his rocket powered boxing gloves at you. The music was Level 2 from Keio FS 1.
(I might be wrong, I haven't played it in aaaaages)
Rami Chan no Oedo Sugoroku for PSX was some kind of 3d board game - the whole thing is in japanese so I didn't even bothered trying to understand anything out of it. The story revolves around some kind of room with treasure in it which everyone is trying to get, but at the end they totally fuck up in a VERY funny way. It included some cool FMVs, thats how I know that part...
