Are you sure that's the prototype ds? CAuse the ds has a touch screen you know. And if I'm not mistaken those are images of Mario & Luigi 1. Mario & Luigi 2 doesn't display the action on both screens like that unless you're in battle or the babies have been separated by going into a cave. I do'nt think that's real.
If you tell us your source and give a link I'll stop being so skeptical.
It sounds like it something they made before they got the dev kit so they could goof around with some ideas.
The only problem is that the ds has an arm9 and an arm7 processor while they seem to have hooked to GBAs with arm7 processors together. Not an accurate, but if they were just goofing around with it I suppose it's fine.
[quote author=triforcemario link=topic=21934.msg122195#msg122195 date=1136226523]
Perhaps is could be a prototype of the DS before the concept of the touch screen was thought of.
[/quote]
Doubt it. The touch screen was the selling point of the DS. I doubt that wasn't in the plans at some point.
Like I said, I don't think nintendo built this. I think the team that made mario and luigi 2 made it.