Looks like an awesome stage.
I do have some suggestions for it (or maybe an alternate). Although it wouldn't be as true to the original stage in SM64, I think for gameplay's purposes, it would help improve the stage.
I feel as if the rotating platforms should be fall-through, because it's going to be difficult to navigate through them (it might take a double jump); because of this, it'd be easy to charge up a smash attack and kill your opponent while they're simply trying to jump on over.
There's quite a big gap between the two gray platforms to the left of the rotating ones. Maybe an additional platform (that visually fits in with the stage) could be added? I just think that it'd be unfair to characters like Ganon that would always end up using an up-b simply to navigate between the two. Actually, looking back at the video, I suppose it's manageable. So nevermind that point.
Finally, I'd definitely think it'd be cool to see this stage with an alternate or updated background. Kinda how Rainbow Cruise had some green valleys below the playing field (in SM64 it was just a sky), it'd be interesting to see a newer interpretation of the stage's background with more visually appealing elements. A simple background port would work nicely.
Well, the descryption in youtube says that everything can change, and that the way the platforms work will probably change, so they are reachable from below. I will probably make it in 3 different ways, so in one is just like in SM64 and the others are more playable.
About the background, I don't know, maybe I look for some background, but that would be the last thing to look into. After all, that part is just importing something and make it fit the lighting, which isn't difficult at all. I'll look into it when I'm mostly finished.
Is this stage going to be auto-scrolling through the entire level, or just the part in the video? You posted some screenshots on the last page that showed different parts of the level. Either way's cool, just wondering. Looks awesome so far!
The idea is having different versions of the stage, in different placements. They're in different layers, so they can't be played as a whole. But sure big areas are possible, but a scrolling version isn't viable.
By the way, stagers, take a look to this and, if you feel like it, test it. Feedback is appreciated.
http://forums.kc-mm.com/index.php?topic=47160