Fourteen hours in and I finally finished the main game and all 198 puzzles. Now it's just onto the bonus puzzles.
Edit: Also if you're looking for user made content these sites have a bunch of QR codes
http://www.abload.de/gallery.php?key=qKgqHUQG
http://hikuosu.tenkai.ws/joyful/joyful.cgi
http://img840.imageshack.us/img840/4851/1323381168041.jpg
http://img190.imageshack.us/img190/7983/1323381324263.jpg