If any of you are feeling particularly masochistic maybe try solving this puzzle I made in early 2015: It's 64*64 divided into 8*8 chunks and the end result should be a 64*64 square as well.I don't think there are any obvious edges.
I'll probably post the solution later, but I want to see if anyone cares to try~
(also let me see your solution or how far you got! It might be wise to split the thing into the individual pieces first.)
Good luck~ :D