ok, here's some stuff:
Inner ring Oasis world, inspired by Cmb's post, no secret exit things, because of the levels I played, the 2 exit ones wouldn't fit into an easy , sunny level environment and the other ones that might have 2 exits don't really have any usable information in the CMS.
http://img820.imageshack.us/img820/7874/oasisu.png
Outer Ring Sky Island world:
Air Arena's normal exit leads to Violet Velocity and vice versa, the secret exits lead to Sky Castle West or THUMP.
Funny thing is, after I put these levels together, I noticed that the land ones all have blue terrain, so the island is blue.
The thing right next to the vine is supposed to be a pipe that gets you to this world.
http://img28.imageshack.us/img28/1105/skyblueland.png
As far as putting together the whole thing is concerned, I have a little plan here using the drafts I made so far.
http://img703.imageshack.us/img703/9400/78463375.png
I stands for inner ring, II for outer ring.
red is what we don't have a draft for yet, you can see we'd need 3 more worlds on submaps for this, plus a hub and a final world.
My idea was to make it not completely symmetrical like a double ring, because that would probably make it really annoying to arrange multiple areas into the main world and there woudn't be much space for hub world and final world levels, I think we should have at least a few of them.
yeah.