Ideally I would hope that Sakurai did his homework and added music from all fronts. If anything I'd say Arena is the most likely to get overlooked (Even though it has the best soundtrack, I really want it in the game).
I wonder how many remixes we'd get. A lot of the soundtrack from Rayman 1 wouldn't need it unless you wanted to add more flavor. Rayman 2 would need it the most considering the weird way the music works in levels (The Final Battle and The Precipice could be added untouched just fine though). And Rayman 3's Hoodoo theme, while a banger, I would remix to be faster-paced. (And add the Snowboard Race theme cause that song bops). Origins and Legend music are also just fine to add.
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On another note, guys. I was trying to get my motivation up so I doodled a quick thing in a couple of hours. Sorry if it's kind of hard to see:
View attachment 290442
So y'all know how the general consensus with Rayman is to copy paste his Origins and Legends moveset into Smash for his regular attacks? I mean, sure, but I honestly would try to have fun with a few of his attacks.
Here, we have my proposed F-Air concept. The animation begins with Rayman performing a front flip mid-air, getting a hold of his torso, and brutally dunking it like a basketball on the opponent's head. The torso would travel downwards and magnet its way back up. The dunk hit has a meteor hitbox, while the torso projectile is just a weak projectile that knocks them off a bit.
The move would have a slow start-up, similar to DK's F-air, however, the end lag would depend on if Rayman is holding down the attack button or not. If it was just a tap, he won't throw the torso and recover quickly. If he holds the button, the torso will travel an extra second and come back to him, and then will he be able to act again, so only use the torso projectile in moderation or as a landing tool.
When using his Helicopter Hair, Rayman would not have access to this move and instead have his forward kick from Origins and Legends.