World 4-1 (Super Mario Bros.)

World 4-1 is the first level of World 4 in Super Mario Bros. and the thirteenth level overall in said game. This level introduces the Lakitu and Spiny enemies in the series.

Layout
The level starts with a pipe containing a Piranha Plant. Once the player jumps over the pipe, Lakitu will appear and begin throwing down Spinies, and will continue to do so throughout the level if Lakitu isn't defeated. Also next to the pipe are two ? Blocks, with the bottom one containing a power-up. Afterward is stretch of land with several coins and ? Blocks, and above the second to the right ? Block in the row of four is a Hidden Block containing a 1 up Mushroom. After the row of blocks is a stone pillar followed by a couple of pipes, and another Lakitu will appear in this area is the previous one was defeated. Through the second Warp Pipe is an underground area with some coins and another power-up in the block above the exit pipe. After the entrance pipe is a row of blocks, with the third from the left also containing a power-up. After the exit pipe are some gaps and another stone pillar before the stone stairs leading to the flagpole, which has a Coin Block before it.

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 Hidden Block near the end of the level above the bush on the ground, and the score to beat is 32000. The Red Coin locations are:
 * In the ? Block above the first power-up
 * In the top left ? Block at the next formation
 * At the end of the row of coins after the first pipe
 * In a ? Block on the bottom row to the right of the pit, after the pipe to the underground area
 * In the coin block at the end of the level

Level statistics

 * Power-ups: 3 (Magic Mushrooms or Fire Flowers)
 * 1 up Mushrooms: 1
 * Secret areas: 1

Mondo 4-1 (Super Mario Bros.)