Here is a thread that PixlBit started a while back that has a bunch of levels you can try:
http://www.pixlbit.com/news/2365/pixlbit_creates_super_mario_maker_levels
I also wrote a blog about Mario Maker a while back.
http://www.pixlbit.com/blog/11139/carys_top_five_favorite_diy_games
--Cary


