World 1-1 (Super Mario Bros.)

World 1-1 is the first level of World 1 in Super Mario Bros. and is the first level in general. The first screen of the level is also the game's title screen when starting it up. It contains the basics of the Super Mario Bros. game, getting the player ready for the journey ahead. The level consists of Super Mushrooms, standard enemies such as Goombas and Koopa Troopas, a lot of Coins, a hidden secret bonus area that will allow the player to skip most of the level, Fire Flowers, deadly pits, and a flagpole at the end.

Super Mario Bros.
World 1-1 starts out on a brick path. As Mario moves forward, a Goomba appears and starts walking toward Mario. The red-clad plumber also reaches the first Question Block of the game, and afterward the six block triangle formation of ? Blocks and regular brick blocks (with a Super Mushroom inside the left block). A set of Pipes await Mario with Goombas located in between the plumbing. The final pipe among the set leads to a bonus area of coins and can be entered to bypass much of the level. After that, assuming the pipe was not taken, there is hidden 1-Up Mushroom Block and a gap followed by another Question Block containing an item, possibly a Super Mushroom or Fire Flower, depending on Mario's health. Additionally, Goombas start falling down from a long row of blocks above.

Afterward, a block down below contains ten Coins that Mario can retrieve by jumping repeatedly underneath the brick. Then there is a notable ? Block triangle formation, which contains no regular blocks. The top block contains a Fire Flower (or a Super Mushroom if Mario is small). Upcoming are some more Brick and ? Blocks, followed by a pyramid-like set of unbreakable blocks with a gap in the middle. After that is another set of unbreakable blocks, this time with a gap in the middle that Mario can fall into and get killed. Just following is another pipe that cannot be entered, accompanied by two Goombas and a set of ? Blocks with coins inside.

Lastly, Mario reaches the ending staircase for the level, and the Flagpole afterward, which is reused in all underground and underwater stages in the game.

Donkey Kong
Mario and Pauline are in World 1-1, with a Warp Pipe and 3 Question Blocks to the right, and Pauline gives Mario a Mushroom. Donkey Kong Jr. peeks to see what their doing and Donkey Kong falls on Mario, but Mario picks up Donkey Kong and Donkey Kong exclaims "HELP!", and Donkey Kong Jr. jumps beside Mario holding Donkey Kong, setting the scene for Donkey Kong Jr..

Enemies

 * Goombas
 * Koopa Troopas

Trivia

 * Due to its iconic notability, the level has been re-created in many games, including Super Mario Advance 4: Super Mario Bros. 3, New Super Mario Bros. Wii, New Super Mario Bros. 2, and Super Smash Bros. Brawl, where it appears as a stage named Mushroomy Kingdom in which it is an old desert, rather than a grassland.