Just like the tittle says, when we are in the hub and we are picking the difficulty, world, and zone, we should also be able to pick the completed checkpoint we have already done.
I am personally fine with the difficulty of world 2, but the zones are just a lot longer and grueling than world 1 ever was. It would be great to have our completed checkpoints saved, so that for those who do not have 2+ hours free, we can hop back in right where we left off when we log in again.