When designing a world, it's always a good idea to have some kind of theme or motif, something that you can then draw other ideas from. This is one of the things that makes concept art valuable - it takes an idea and visualizes it into something concrete that you can base the final product on. About a month ago, the texture contest ended for Arid Canyon Zone, and the winning entries were chosen. While I didn't think of it at the time of posting the contest, I think the level can be best represented by an old cartoon:

I find it a little odd that nobody has visualized this kind of crosscasting before, but it can be safe to say that most of the stuff you find in a Road Runner cartoon will be found in Arid Canyon. Canyons (duh), tunnels through the mountains, railroad tracks, etc. There's also going to be a few other additions, such as oil that you can slip and slide around in, and rope pulleys that you can hang on and ride (think Hydrocity except tilted sideways).

I'm a little stuck with Castle Eggman right now, so Arid Canyon gives me something new and fresh to flesh out. Maybe I need to get more concept art for CEZ.

Got any ideas that you think would fit good in Arid Canyon? Post them here. Note that all ideas you post become our property blah blah blah you can't sue us if we use it blah blah etc. etc. (I have to say that).

Update: When I'm talking about ideas, I don't mean something generic, like "mine carts" or "a space station" or "a pool of lava". What I'm looking for are platforming challenges or puzzles. For example, "take the ropes you can hang on in Hydrocity Zone, turn them on their side, and have Sonic hang onto the ropes, jumping between several of them, to cross a cavern."