Natasha

I need tips or advice please. My son was playing this game and worked very hard to beat the game. However, once he got to the part where Mario is at the bottom of the well he died when the ghost was in a car and the other in an airplane. Once he died the game made him start over from the very beginning of the game itself. Can anyone help me understand why it started over and if theres a way to fix this? My son is still young and took this very hard as I'm sure adults would too. Anything helps as my son is devastated. thank you in advance from a mom who doesn't know her video games.