[quote name='FriskyTanuki']You don't need to make anything, as you can focus on just playing the story levels and all of the community levels that others will make.[/QUOTE]
99% of them look boring as hell though... it's like they forgot the platforming is supposed to be fun.
The best things I've seen are the tetris level and calculator level. I'd wager neither are overly fun to play, it's just neat to see that people made something like that with the engine.
Floaty jump over here. Grab dangling thing and scamper up, jump some more, collect some bubbles, floaty jump, get some items for level building, rinse, repeat.