The KNOCK KNOCK puzzle was an even harder challenge because they have no map to follow. They have blocks over the whole bottom row of doors, and the 2 top left hand corner dooes are covered. The box cover would be fine IF there was a map inside to follow.
There is a very small full picture, but when trying to find the little details of all the door boarders and doorsteps is almost impossible.
I don't think I would ever buy another Melissa and Doug puzzle