This is the first Mario game that included an overhead world in which you could change levels and use powerups in between stages to help you progress first. This is also the first game where you could fight different bosses besides Bowser. A Bowser Jr. would appear at the end of each stage and you would have to stomp on their head 3 times to beat them to save the king who was turned into some kinda animal, usually looking pretty stupid being that animal too. Whats pretty cool is that if you look closely you can see that the whole game is played on a "stage" as the props are all bolted down, and at the start of the game there is a curtain that opens up like in a theater.