Simplify the following text for a Grade 4 native English-speaking person.
Original: Super Mario Bros. has spawned many sequels : Super Mario Bros. : The Lost Levels ( named Super Mario Bros. 2 in Japan ) , Super Mario Bros. 2 ( released in Japan as Super Mario USA ) , Super Mario Bros. 3 , Super Mario World ( which had the working title of Super Mario Bros. 4 ) for the Super NES , Super Mario 64 ( for Nintendo 64 ) , Super Mario Sunshine ( for GameCube ) , New Super Mario Bros. for the Nintendo DS , and Super Mario Galaxy , New Super Mario Bros. .
Simplified: In Super Mario Bros. , Mario goes in the Mushroom Kingdom .