As a major change in the Mario series, Super Mario Bros. 2 allows you to choose from four characters, each with his or her own advantages and disadvantages.
Mario
Mario’s got solid jumping power and speed, but his jumping power takes a small hit whenever he’s carrying an item.
Luigi
Luigi has the best jump ability, but he loses the most jumping power out of anyone whenever carrying an item.
Toad
Toad has the least jumping power, but the highest speed in the game. On top of that, items do not hinder his jumping power at all.
Princess Toadstool
In terms of speed and jumping power, Princess Toadstool is on the low end of the spectrum. But her ability to float in the air more than makes up for these shortcomings.