Super Mario Bros is Nintendo's landmark 1985 side-scrolling platformer, where you run and jump through the Mushroom Kingdom as Mario to rescue Princess Peach from Bowser.

You can play it officially through Nintendo Switch Online or the NES Classic, and many free, unofficial browser ports let you play it instantly with no download.

Standard browser controls use the arrow keys or WASD to move, with the jump held longer for higher jumps and Shift or CTRL to run and throw fireballs. It runs on desktop and most mobile browsers.

Super Mario Bros is a side-scrolling platformer released by Nintendo in 1985 for the Nintendo Entertainment System (NES), in which players guide Mario (or Luigi) through the Mushroom Kingdom to rescue Princess Peach from the villain Bowser.

It helped define the platformer genre and launched gaming's most famous franchise, marking its 40th anniversary in September 2025. The game first appeared in Japan on the Famicom on September 13, 1985, before reaching the NES worldwide.

Its design — tight jumping, hidden secrets, and steadily escalating challenge — became the template that countless platformers followed. You play across eight worlds, each ending in a castle guarded by Bowser (or a decoy). Two players can alternate turns as Mario and Luigi.

Its influence is hard to overstate, but by modern standards it's short and punishing: there's no mid-level saving in the original, so a single mistake can cost real progress.

Key Insight: "Super Mario Bros is widely credited with reviving the home console market after the 1983 industry crash, and its precise jump physics still set the standard platformers are measured against." To play Super Mario Bros, move right through each level by running and…

Grab power-ups to grow stronger, avoid pits and hazards, and clear each castle — defeating Bowser — to advance toward rescuing Princess Peach. The structure is simple but demanding. Each of the eight worlds has four stages, and the final stage is a castle.

You have a set number of lives; falling in a pit, touching most enemies while small, or running out of time costs one. Collecting 100 coins grants an extra life, and stomping enemies in quick succession builds bonus points.