To proceed, Mario must collect enough stars to open specific doors, a gameplay element borrowed from Super Mario 64. There are 35 stars to collect in total. Mario must explore different areas to reach his aim of saving the princess. There are five different worlds, each guarded by a boss. The worlds consist of the Fun Fair (the main starting area), Grassy Greens, Frosty Frontier, Shifting Sands, and Bowser's Castle.