Nintendo of America thought the game was too hard and took another game , called Doki Doki Panic , and released that instead under the Super Mario Bros. 2 name . They found one in Yume Kojo : Doki Doki Panic ( Dream Factory : Heart-Pounding Panic ) , another Nintendo game developed by Miyamoto , which he had actually spent more time developing than The Lost Levels , which was released as Super Mario Bros. 2 in North America and Europe and later as Super Mario Bros. .