I may have already completed it, but the game just keeps giving!
Today, while trying to get all the big coins (I’ve all of them on the first two worlds, and most on the fourth now), I stumbled across a secret exit in a ghost house. That opened up yet another level for me to do!
I also had a great time playing with my daughter helping on the game pad. She was laying down blocks over holes, and helping me reach coins that would otherwise require a powerup or a special Yoshi. It was awesome.