I had this massive Redstone contraption world called "Oky's Base", and it took you through about fifty different Redstone mechanics. This involved sliding doors, launching anvils, secret buttons, and even slime cannons. Unfortunately, I think it was deleted when my old computer [2012 Toshiba, ancient I know] was wiped to make room for my brother's files, as he inherited it. I'm not completely sure I deleted it, I'll have a look and see if I can find the world file on my new computer.