World 4 (Super Mario Bros.: The Lost Levels)

World 4 is the fourth normal world that is first featured in the game Super Mario Bros.: The Lost Levels. After the player has beaten this world, he/she will have access to World 5. It is also the first world to introduce the red Piranha Plants, replacing the green Piranha Plants from the first three worlds.

World 4-1
The player will start off outside, and will find two red Piranha Plants along with a Lakitu. The player will see a gap in between a line of Brick Blocks. The block that the player can hit with a normal jump contains ten coins. The player will then see another red Piranha Plant, and after the player passes this pipe, Lakitu will float away from the screen. The player will see seven ? Blocks, the last one containing a power-up, and the rest containing coins. The player will then see a Trampoline, and water which the player cannot swim in. The player should jump over the water using the Trampoline.

Another Lakitu will chase after the player. Soon, the player will see three ? Blocks, two containing coins while the other contains a Poison Mushroom, along with a pipe with a red Piranha Plant inside of it. The player will see two ? Blocks, one of them with a coin, and one with a power up, while seeing pipes on top of a row of ? Blocks containing coins. The first pipe along the row of Blocks is an underwater shortcut that will just take the player to the first pipe he/she will see on the bottom. The shortcut will have Bloopers, and Buzzy Beetles, along with coins scattered around the place. A ? Block with a coin can be seen here, along with a Brick Block containing a Vine which will lead to Coin Heaven, however he/she will then go back to the place where the player couldn't swim in the water. The player should see some more red Piranha Plants, and a staircase with a Goomba, along with the Flagpole. He/She will now have access to World 4-2.

World 4-2
After a couple of steps, the player will see Bill Blasters surrounding a lone ? Block containing a power-up. Then, the player will see a Brick Block containing a Star, a couple of Buzzy Beetles, and two ? Blocks with coins. Now, the player will see a Trampoline, and two rows of Brick Blocks with a Koopa Troopa on the top one, along with Lakitu's appearance again. If the player kicks the Koopa Troopa and runs along with it, it will defeat Goombas and Koopa Troopas, eventually giving the player an 1-Up. The Lakitu will now disappear.

The player will soon see more Bill Blasters, and a lone Koopa Troopa, along with nine ? Blocks. The one above the first Bill Blaster contains a power-up, while the other ones have coins. The player will see another Koopa Troopa, and a Brick Block hanging right under a pit which contains ten coins. The player will see a Hammer Bro., and then will have the option of going up or down. If the player chooses to go up, he/she will fight another Hammer Bro., however if he/she chooses to go down, they will see two red Piranha Plants and seven ? Blocks containing coins. The player will see another red Piranha Plant, and some blocks the player can jump on top of. There will be a Koopa Paratroopa here, and the Flagpole. Slide down it to open up World 4-3.

World 4-3
The player starts off at a platform. He/She will make a big jump to another platform with a Trampoline, and a steady platform, along with a moving one. Then, the player will see two platforms that are connected together, and will fall if he/she is standing on them. Then comes another moving platform and Koopa Paratroopa. The player will have to make another huge jump, except this time, the player must bounce off the Koopa Paratroopa so that he/she makes it to the platform which has coins on it. The player will then see another trampoline, along with coins and another moving platform. A lone ? Block under the moving platform contains a power-up. After the player makes it to the next set of platforms, and jumps on top of the falling one, Bullet Bills will start coming after the player. The player will see another set of platforms connected by a rope, and they can either jump to the platform which contains coins, or the platform which has a Koopa Troopa, along with a big gap the player will have to jump from. If the player takes the top route, he/she can use the falling platform and jump off it to the next platform, while collecting coins in the air. The player will see two more Koopa Paratroopas, and two floating blocks in the air. The player can then see the Flagpole from here. Players should slide on it to go to World 4-4, the final level in World 4.

World 4-4
Starting off, the player will see a Koopa Troopa walking on seven ? Blocks, and a huge firebar. Six of the Blocks contain coins, while the one next to the firebar contains a power-up. The player will see a regular firebar, along with three Goombas. Another huge firebar is seen here, the player will have to jump on top of the stone blocks the firebar is anchored on, and a regular firebar can be seen below, along with a moving platform that will go vertically.

The player will advance, and find a firebar, along with three Koopa Troopas. He/She will then see a falling platform, which will safely take the player to the ground on the right of it. A firebar and a Hammer Bro. will be seen here. Then, the player will see a red Piranha Plant, two firebars, and three Goombas. The False Bowser in this level will start shooting fireballs at the player. If the player chose to go through the middle route of the firebars, he/she will find a Hidden Block, which contains a power-up, and another one beside it, which contains a coin. Also, if he/she chooses to go underneath that one, another Hidden Block with a coin can be found. A red Piranha Plant and a moving platform can be found here. The player should then jump to the Stone Block. A Podoboo along with a firebar with a False Bowser can be seen. Defeat the False Bowser here, and the player will rescue four Mushroom Retainers, advancing to World 5.