[STHX]

I don't know why, but that pic made me think of this:

Speaking of which, DKC2 has some interesting concepts for potential Zones which could be explored.
This is another one I would like to see:

[Mr. Mash]

I doodle'd this up;

The background would be hazy with silhouettes of trees, and broken trees. The "grass" would be made of old dry pine needles, and the as for the ground I imagine it to be like Planet Flora's from Ristar, only the whole level's pallette would be very desaturated and grey. It isn't very clearly drawn, but that's some water with logs floating on top at the bottom there. The water could maybe sap sonic's rings, like in the special stages in The S Factor.