I've heard many people say they want a Green Hill Zone in Brawl since it's supposed to be one of Sonic's staple stages and has even evolved in different Sonic games (from Emerald Hill Zone to the similar stage in Sonic 3D Blast. It was also featured in Sonic Adventure 2 Battle as a secret stage).
This stage should remain 2D, as did Mushroom Kingdom, but it shouldn't be a cheap stage where you can easily KO yourself by walking off the stage. Think Dreamland. Also, the hills on each side are not solid, meaning you can easily fly through them (the opposite of the buildings in Fourside for example). Also the ceiling and the side walls aren't short. The stage gives you ample room to come back after a strong impact, but it's not as huge as Dreamland, nor is it as small as Flatzone.
The stage has two hills on each side.
Two platforms that on the top middle of the stage.
One platform that remains beneath the two.
Right now, they don't move.
If they did move, they'd move up and down in different intervals.
Also, if they didn't move, the bottom one could crumble and reload after a while.
This version has a longer and lower bottom platform and the top platforms don't move.
Discuss, etc. I added the characters in there too so people could see how they'd compare in terms of size.
This stage should remain 2D, as did Mushroom Kingdom, but it shouldn't be a cheap stage where you can easily KO yourself by walking off the stage. Think Dreamland. Also, the hills on each side are not solid, meaning you can easily fly through them (the opposite of the buildings in Fourside for example). Also the ceiling and the side walls aren't short. The stage gives you ample room to come back after a strong impact, but it's not as huge as Dreamland, nor is it as small as Flatzone.
G r e e n - H i l l - Z o n e

The stage has two hills on each side.
Two platforms that on the top middle of the stage.
One platform that remains beneath the two.
Right now, they don't move.
If they did move, they'd move up and down in different intervals.
Also, if they didn't move, the bottom one could crumble and reload after a while.
G r e e n - H i l l - Z o n e

This version has a longer and lower bottom platform and the top platforms don't move.
Discuss, etc. I added the characters in there too so people could see how they'd compare in terms of size.