Can't believe that someone haven't posted these yet, I found them really cool
Making of Overgrown (big <3) and Crash (also big <3, slightly less tho!).
http://www.gametrailers.com/player/27358.html
http://www.gametrailers.com/player/27444.html
Found myself going back and forth checking out how each area changed, really cool stuff. Wish more developers would do this kinda stuff for bonus material and such~