Wonderland was severely disappointing. It had a lot of potential, but the HORRIBLY designed forest and the annoyingly hard to remember paths made it a very unlikeable level.

Also, I liked Atlantica in II, but it kinda bugged me that they were basically saying "Yeah, remember all that plot that happened in this world in the first game that you had to suffer through the awful controls to advance? That didn't happen. THIS is how it happened." So, I would live without ever seeing it again. Though... Aqua in a seashell bikini... hehe.

The only world I honestly never want to see again is Monstruo. GAH.