I posted about this a while back, with an invisible 'player' sprite and a pinned 'display' sprite, it's reasonably simple to replicate rotation based on platforms , though a native application of simple slope adjustment would be awesome.
@Tokinsom: Well, the platform behavior can move on slopes, but it can't automatically rotate on them, nor is it capable of properly traversing curves. But, yeah, general improvements are a good idea all round.
@JohnnySix: To be fair, using two separate sprites is a well-known technique. And crouching is easy, make a separate animation for while the player holds down. :p
I didn't meant to accuse you of anything, mate. XD Still, it's a rudimentary thing that only works with specified objects, and can't work with curves.
Sonic the Hedgehog is practically the pinnacle of tight, well-designed platform rotation physics, IMO. When there's a guide on how to replicate it and existing examples out there, might as well copy from the best!