What open source platform game was modeled after a Nintendo game released in 1985 that required players to rescue Princess Toadstool?
Super Mario Bros. Super Mario Bros. is a platform video game developed and published by Nintendo for the Nintendo Entertainment System home console. Released as a sequel to the 1983 game "Mario Bros.", "Super Mario Bros." was released in Japan and North America in 1985, and in Europe and Australia two years later. In "Super Mario Bros.", the player controls Mario and in a two-player game, a second player controls Mario's brother Luigi as he travels through the Mushroom Kingdom in order to rescue Princess Toadstool from the antagonist Bowser.
Dr. Mario Dr. Mario (Japanese: ドクターマリオ , often stylized as D℞. Mario) is a 1990 action puzzle video game produced by Gunpei Yokoi and designed by Takahiro Harada. Nintendo developed and published the game for the Nintendo Entertainment System and Game Boy consoles. The game's soundtrack was composed by Hirokazu Tanaka.