World 3-1 (Super Mario Bros.)

World 3-1 is the first level of World 3 in Super Mario Bros. This stage marks the debut of the Hammer Bro. enemy in the series.

Layout
The player starts off next to some ? Blocks, with the right-most block containing a power-up, and Koopa Paratroopas jumping toward the player. Across a gap and some pipes (the second of which leads to an underground area with some coins and another power-up, and exits out to the fourth pipe) is a bridge with some Goombas, and above the bridge is a Hidden Block with a 1-Up Mushroom. In the left-most block of the Brick Block formation afterward is a Super Star, that can make getting through the Hammer Bros. up ahead easier. In the second ? Block on the block formation with the Hammer Bros. is a power-up. A Springboard afterward can help the player get over the Brick Blocks ahead, and the right-most block on the top row has a beanstalk that leads to Coin Heaven. Next is a set of stone stairs with Goombas walking down them, followed by a group of blocks and enemies, with the bottom-right ? Block containing a power-up. In the row of blocks afterward, there is a Coin Block in the second block from the left. Finally, there is a stone pillar followed by some Koopa Troopas walking down the stone stairs before the Goal Pole.

Super Mario Bros. Deluxe challenges
In Super Mario Bros. Deluxe, the player can collect five Red Coins, find a hidden Yoshi Egg, and get a medal based on their score. The Yoshi Egg is found in a Brick Block underneath the beanstalk, and the score to beat is 45000. The Red Coin locations are:
 * In the middle of the first row of Brick Blocks
 * In the opposite block of the power-up in the underground area
 * In the ? Block on the left at the Hammer Bros. area
 * In the top-left ? Block in the group of ? Blocks
 * After the stone pillar

Enemies

 * Koopa Paratroopas
 * Piranha Plants
 * Goombas
 * Hammer Bros.
 * Koopa Troopas

Level statistics

 * Power-ups: 5 (Four Super Mushrooms or Fire Flowers and one Super Star)
 * 1-Up Mushrooms: 1
 * Secret areas: 2

Mondo 3-1 (Super Mario Bros.)