Remember when you played Sonic Adventure, and how great of a game it was? And how you know you HAD to play "Mario and Sonic at the Olympic Games" because, you know, it's Mario and Sonic, against each other! Well, if you don't, I do. I was scouring the internets the other day, and stumbled across Sonic Adventure. Then, it happened. An idea popped into my head. Why not take Sonic Adventure, and use the game play style and open world story mode and combine it with Mario characters and make Mario and Sonic Adventure? I don't know, I just thought it would be cool. Thoughts?

Not happening, Miyamoto (Father of Mario) and Naka (Father of Sonic) have both said this won't happen, only because the game would be too hard to make.

Most likely: A super-speedy power-up in Mario where he dresses up as Sonic (and Luigi as Shadow). I don't think Mario has had a speed power up yet (other than Starman); it would be great for speedruns!

Or at least a blue hedgehog as a reference to Sonic!

Crash and Sonic would make a better duo.
Their both has-beens

Not a very well thought out idea, I think spin-offs like Mario & Sonic go to the olympic games are ok for those who enjoy them, but really a Mario & Sonic Adventure type game? I think Miyamoto would think twice, I'm pretty sure he wouldn't want his characters to fall into mediocrity like Sonic and friends. The olympic games games were pretty much product tie-ins with the actual olympic games, in retrospect they're not really that fun, they're basically just minigame collections and the devs who handle these games are Sega, it wasn't surprising they'd be bad.

That's a good point...

i beg to differ about those games being bad...my son and i love them. I like playing minigames like that

I have to say, the original Olympic games were good. As for the Winter and Summer 2012, can't because I never played them, but I heard Summer was awful.

A platformer would be nice. I don't really care how difficult it is to make since it has been a game I've been waiting for since 1991.