Original: Mario, Luigi and Yoshi set out to save Princess Toadstool and Yoshi's dinosaur friends, exploring Dinosaur Land for Bowser and his Koopalings.
Simplified: In this game, Bowser has kidnapped Princess Toadstool after she, Mario, and Luigi had a vacation in Dinosaur Land. Mario and Luigi must rescue her and seven Yoshi eggs from Bowser and his Koopalings.