Super Mario Bros./Secrets

Gameplay
The game is set up in eight worlds divided into four levels each. In each level, the player runs or swims through the level, dodging enemies and obstacles while grabbing power-ups and coins. The game can be played by either one or two players. In two-player mode, the players take turns playing the one-player game with player two taking the role of Mario's brother Luigi.

Items

 * Super Mushroom - Yellow mushroom with red spots that transforms Mario into Super Mario. In Super Mario All-Stars, it is a red mushroom with white spots.
 * Fire Flower - Glowing flower that transforms Super Mario into Fire Mario, and small Mario into Super Mario.
 * 1-up Mushroom - Yellow mushroom with green spots that gives player another life. In Super Mario All-Stars, it is a green mushroom with white spots.
 * Coin - Every 100 coins will give you an extra life.

World 1-1
A straightforward outdoors level. You can enter the fourth pipe to reach an underground bonus room. To the right of the fourth pipe is a hidden 1-up mushroom. In most versions of the game, it is not hard to find: stand in front of the hill in the distance and jump straight up. In Super Mario All-Stars, there is no hill, but the 1-up block

World 1-2
An underground map. If you walk along the bricks at the top of the level, you can reach a secret warp to world 2, 3, or 4.

World 1-3
An outdoors world on the treetops.

World 1-4
This is the first Bowser's castle and is fairly straightforward. Towards the end you will find a large empty space, where you can find six hidden blocks arranged in a pattern. These don't really serve any purpose.

The Minus World (Level -1)
This is a glitch world. In the NES and Game Boy Advance versions, this is a never-ending underwater world. When you reach the end of this "level", you are taken to the start of the level. There are no powerups and the only way to end the level is to die or run out of time. When you die, you are taken to the start or middle of -1. In the Famicom Disk System version, this is a three-level world with some strange quirks. The game ends after the third world as though you completed the game at world 8. The Minus World is only available in the NES, Famicom Disk System, and Game Boy Advance versions.

To access this glitch, become either Super Mario or Fire Mario. Go to the end of World 1-2 and stand on top of the pipe. Go all the way to the right, and then one square left. Knock the brick above you out. There should now be the wall with one brick attached and a gap.

Walk to the edge of the pipe without falling off. Now for the tricky part: crouch, then while crouching, jump and hold right so the brick attached to the wall pushes you down in the air slightly. When done right, you will go through the wall. Do not move; you will slide through the wall automatically. Once you are through the wall, enter the first pipe (beware the piranha plant!). Do not walk all the way to the right or the area reverts to the normal warp area when "Welcome to Warp Zone!" appears. (The middle pipe takes you to world 5, and the rightmost pipe also takes you to the Minus World.)