A few of us (me, naju, Navelgazer, branduno and Elementary Penguin) have been making levels in Super Mario Maker for Wii-U. We've started a blog, mefimariomaker.blogspot.com, to show them off. You don't have to follow or friend us or anything to play 'em, just enter the 16-digit ID codes into Super Mario Maker and play! (This does mean you have to own the game and a Wii-U to play 'em, sadly.) Their difficulty is all over the map. If you have the game and want to post 'em too, just send me a MeMail with your email address and I'll invite you! There is no other requirement, besides being a MeFi member, for posting your levels. It's a Blogger blog, so you'll probably end up needing a Google account.