Super Mario Bros./Gameplay

Controls
Continue: In order to continue in the world you were playing after dying, simply press while holding down  at the title screen.

One foot jumps: If a target is off to the side of a platform, position Mario so that one foot rests on the edge of the platform, and one foot rests in mid-air. Then jump up to perform a one-foot jump and hit out of the way targets.

Crouch and Slide: Super Mario and Fire Mario can "crouch and slide" by holding and  to run right, then hold  to duck into areas that are only one square tall.

Mario & Luigi
Mario and Luigi are the heroes and stars of the Super Mario Bros. adventure. When the game begins, they start out small. They can be killed if they are struck by an enemy, or by trying to jump on a Spiny, Piranha Plant, or Bowser while in this form. They can also be killed by falling into a pit at the bottom of the screen, or if they run out of time. They can jump up and punch "?" blocks, but they can not break any bricks. Find a Super Mushroom as quickly as possible to give the brothers a fighting chance.

Super Mario & Luigi
After touching a Super Mushroom, Mario and Luigi grow to twice their original size. With this new found ability, they gain several powers. They can smash bricks with their fist while jumping. They can access the Fire Flower power-up in order to become Fire Mario or Luigi. If they get hit while super (or try to jump on a Spiny, Piranha Plant, or Bowser), they do not die, they merely revert to their normal form. When this happens, they become invulnerable for a short period. They can still die, however, if they fall in a pit or run out of time.

Fire Mario & Luigi
Fire Mario and Luigi have all of the same abilities as Super Mario and Luigi, and they gain one additional power: the power of fire. After taking possession of the Fire Flower, the brothers turn red, and they can toss fireballs from their hands by pressing. Up to two fireballs can be on the screen at one time. These fireballs are even accessible when the brothers are underwater. Fireballs bounce along the floor, and can fall down pits. Beware, there are some enemies which are impervious to fireballs. If Fire Mario or Luigi are struck by the enemy, they will revert all the way back to regular Mario and Luigi, a costly mistake.

Princess Toadstool & Mushroom retainer
While the princess is your ultimate goal, you will encounter and ultimately rescue seven Mushroom retainers until you find the correct castle and rescue the princess. Each time, the retainers will lamentably thank you for your services, but inform you that the princess is in another castle. As the Super Mario series evolves, Princess Toadstool comes to be known as Princess Peach, and one special Mushroom retainer is known as Toad.

Items
A variety of Power-Ups can transform Mario and Luigi in three ways. As Super Mario, Mario gets big, then if attacked by an enemy, he shrinks back to regular size, and continues the game. As Fire Mario, Mario shoots deadly fireballs. An enemies have no power over Invincible Mario—for a time.

The Mushroom Kingdom
The Mushroom Kingdom is divided into 8 worlds with 4 levels in each, providing a total of 32 levels to conquer! In each level, Mario encounters deadly enemies which he can shoot with fireballs or stomp out. The following moves, however, are deadly to Mario and Luigi:
 * 1) Bumping into flames, or members of the Koopa clan, or other dangerous creatures.
 * 2) Running into a Troopa or Buzzy Beetle that you kicked out of the way, but didn't destroy.
 * 3) Falling into a pit or a drain
 * 4) Running out of time before you make it to the flagpole or defeat Bowser.

Mario and Luigi's journey through the Mushroom Kingdom takes them through a variety of terrains.
 * The ground: Here you'll find hills, bushes, and many more land-like features. Discover hidden advantages when you knock your "block" on the blocks.
 * The underground: Everything is made of bricks, but you can blast through them by using your head!
 * Tree-top world: You have to be athletic if you want to avoid a fall!
 * The Castle: The evil Bowser isn't the only challenge you'll have to face to reach the princess in her castle!
 * Underwater world: To avoid getting sucked down the drain, you have to swim like crazy!
 * The suspension bridge: Don't worry about falling off, but watch for flying enemies that attack from below.
 * Coin room: Duck down a pipe and find a treasure room full of sparkling coins. Don't run out of time!
 * Coin heaven: Discover a beanstalk hidden in the blocks, hop aboard, and strike it rich! Cash in!
 * The warp zone: Discover the warp zone, and take a shortcut to other worlds.

Errata

 * Blocks: There are breakable blocks, unbreakable blocks, and blocks containing hidden secrets. Some blocks appear out of thin air when you jump up.  Breakable blocks can only be broken by Mario or Luigi when they are in Super or Fire modes.  Inside "?" blocks you'll find power-ups, coins, and other special surprises.  Regular blocks may also contain power-ups and 10 coins, therefore every block is worth a punch, but don't run out of time!
 * Flagpoles: The flag pole signifies the end of the first three levels in every world. A staircase usually precedes the flagpole, giving Mario and Luigi a high platform to jump from.  The higher to land on the flagpole, the more points you are awarded, up to a maximum of 5000.  It is also possible to score more bonus points depending on when the clock stops (see Secrets).  It is nearly impossible to jump over the flag pole, but in rare instances it can be done, in which case Mario will run endlessly through an empty terrain until time runs out.