Use arrows [↑→↓←] or W-A-S-D keys to move Mario， to jump higher hold the up arrow.
Use Shift/Ctrl to Fire/Sprint. Use P or RightClick to pause.
Click "Options" to change volume, game speed, view mode, touch controls, etc.
Click "Maps" to choose any of the 32 levels or generate a random map.
Super Mario Bros. is divided into eight worlds, each of them containing four levels. Mario has to get to the end of the level by jumping over various gaps and avoiding the enemies on his way. He can use several platforms (some of them collapse when Mario lands on them), stairs in the level, as well as jumping boards. There are also pipes along the way, some of which Mario can enter to visit various secret coin rooms before returning to the level, a bit further ahead than when he left.
Enemies include Little Goombas, Koopa Troopas, Buzzy Beetles, Koopa Paratroopas, Bullet Bills, Hammer Brothers, and leaping Cheep-cheeps. All these enemies can be defeated when Mario jumps on them. Koopa Troopas and Buzzy Beetles cower in their shell when jumped on, which Mario can kick to defeat other enemies with. Koopa Paratroopas lose their wings and fall to the ground when Mario jumps on them. Other enemies include Piranha Plants, and the Spiny-throwing Lakitus, and Mario has to either shoot fireballs at them or just avoid them. Two levels take place underwater. In the water, Mario can swim freely from the top to the bottom of the screen. The enemies in underwater levels are Bloobers and Cheep-cheeps. Mario can only defeat these creatures by shooting them with fireballs.
You can read more about Super Mario Bros. Gameplay here.
Super Mario Bros. game is set up as eight worlds divided into four levels each. In each level, Mario must run or swim through the level, dodging enemies and obstacles while grabbing power-ups and coins.
World 1-1 - Run from the start of the stage, and take the fourth green pipe from the start, and run quickly through the coin room, and complete the stage.
World 1-2 - At the final part of the level with the orange platforms moving up and down, anticipate their presence and jump to the first set of platforms that are droping, to the top of the blue platform in the middle, to the next set of platforms that are rising, and make it to the top of the screen in one fluid motion.
World 4-1 - Beat as normal. To save time, it is possible to jump over the piranha plants. Your jumps have to be timed perfectly though otherwise Mario will be killed by the plants.
You can read more about Super Mario Bros. Walkthrough here.
At here you see the map for Level 32 of Super Mario Bros. Of course all secrets, 1Ups, hidden bonus rooms and secret pipes and vines are shown on it!
You can read more about Super Mario Bros. Maps here.