Summary
I think this is a pretty good stage for GaW. U-Air and N-Air can juggle quite well because of the platform. The low-ish? ceiling means U-Smash and D-Smash and even D-Air will kill a lot faster. Because of the lip, GaW's will almost never kill themselves by screwing up their Up-B (unlike in FD) yet stage spiking (with Up-B and B-Air) is the same like other stages. D-Throw can also meteor smash at the ledge if performed correctly.
As long as you're not playing a super spacy? character like Marth, controlling the space comes almost instantly. Some of GaW's "difficult" MUs are slightly easier to take on in this stage than most.
I feel a bit ridiculous emphasizing so much on the single moving platform but that's the main thing this stage has. It brings the combos and breaks most camps.
Rating
7/10
Character
Just don't CP this against Snake because C4 or N-Air through the platform is a killer. This stage isn't that big which means a surprise U-Tilt can lead to a quick kill (especially because it goes through the platform) and there isn't that much room to bucket brake. His camping, sadly isn't broken by the platform. This stage helps him more than you.
Most MK's will take full advantage of this stage by hopping off the platform into F-Airs or D-Airs and Shuttle Loop will also be a surprise killer because as I've said, its not that big. Also, the platform helps them U-Air -> Tornado. MK controls platforms better than GaW and even though there's only one, GaWs still need to be careful.
Marth is also annoying for basically the same reasons as Snake. Good Marths will control the space better than most GaW because of his larger range. From my experience anyway.
Toon Link is okay to take on, on this stage because the platform gives him a harder time camping and fall through platform -> D-Air works almost every time since its a TL players instinct to run away and camp rather than melee.