World 2 (New Super Mario Bros.)
World 2 is the second world in the game New Super Mario Bros. It is a large Desert-themed world, with enemies such as Pokeys and Lakitus. Bowser Jr. is fought here for the second time in the Tower, and the boss of this world is Mummipokey. This world introduces the idea of Warp Pipes - a means of transportation from one level to another. Unlocking Warp Pipes means that the player can skip some levels, and complete the world without completing all the levels.
 World 2-1
This level starts out with four ? Blocks; in the second one, a power-up can be found. A Pokey will appear as the first enemy of the level. Above the Pokey resides four coins. After a few steps, a Spiny is encountered; near it are three Brick Blocks and a second Pokey. After a few more steps, the first Star Coin can be found, along with a third Pokey. After some more trekking, the player will encounter a cluster of three Pokeys - each on or near a floating platform. The second Star Coin can be found by both a bank of quicksand and another Pokey. After the player passes the second Star Coin, he or she will encounter an abyss that hosts a Pokey and a few more floating platforms. Once the abyss is passed, the Midway Point will be activated. Past this point, three brick blocks and one ? Block is seen. As the player presses forth, he or she will encounter four abysses, each hosting one Pokey. In the fourth abyss resides the final Star Coin in the level. At the end of this abyss, there is a mini-pipe which can only be accessed via the use of a Mini Mushroom. After this, yet another abyss is found; within it are a few floating platforms and a Pokey. Past here, the player must enter a pipe to continue in the level. Inside the Mini Pipe is nothing but a maze and a few clusters of coins.
On the other end of the pipe, there is a cluster of blocks; in the middle block resides a P-Switch. By activating the P-Switch, the small bridge of coins ahead, (located above the final Pokey in the level), will turn into brick blocks. If the player runs across the bridge of brick blocks, he or she can jump to the Flagpole. Once the flagpole has been touched, the level ends.
 Star Coins
 World 2-2
This level starts out with three orange platforms, each hosting a Koopa. Underneath the second platform resides a ? Block containing a power-up. After the first abyss, the player will encounter a Lakitu. Kill the Lakitu with a fireball or shell and take its cloud. Using the cloud, ride to the top of the level where there is a line of coins that reaches to the sky. The first Star Coin should be located here, right before the second set of orange platforms. The player will find several coins and blocks by here. Past here, two more small abysses can be found, followed by a cage of blocks containing a few coins. Another Lakitu will appear by this point. Once again, three orange platforms hosting Koopas are found, followed by a pipe within an abyss. To the right of this pipe is the second Star Coin hidden underneath a small mass of land. Mario and Luigi will have to ground pound some bricks to obtain this Star Coin. A red pipe can then be found, along with several Bricks and ? Blocks. Located high above this cluster of blocks reside several coins which are only accessible via the use of a Lakitu Cloud. By this cluster of blocks is the checkpoint. Another Lakitu can be found, along with several blocks and two pipes. By entering the green pipe, the player will be rocketed up to a type of Coin Heaven. The final Star Coin is located in this Coin Heaven. Whether or not the player enters the coin heaven, he or she will have to run across tilting mushrooms that lead to the flagpole. Once the flagpole is touched, the level ends.
 Star Coins
 World 2-3
World 2-3 is the third level of the desert world from the game New Super Mario Bros.. The level features many Piranha Plants ala Super Mario World 2: Yoshi's Island and the first appearance of the Super Piranha Plants.
The level begins in a desert, then Mario or Luigi enters through a pipe and the level continues inside the sewers, where the Mario Bros. enter by sliding. In some platforms, Mario or Luigi will have to Ground Pound to pass through them, also, there are "blocks" which are sensible when Mario or Luigi collides with them depending of which direction is the arrow. Crossing one of these blocks with the arrow in the bottom at the beginning will lead the player to a Brick Block with multiple Coins inside. After ground-pounding and crossing this part, the Mario Bros. will have to solve a small puzzle to take one of the Star Coins, located above a Piranha Plant and also go to the next part of the level. After crossing the puzzle, Mario or Luigi will cross the midway point and then they'll have to slide in order to proceed. In the left corner, they can find a ? Block with a coin inside and in the left of this block there's an invisible block with an 1-Up Mushroom inside it. The player can't reach the big platform of the right because the player first needs to press the ? Switch to proceed and pressing it will make the water level go up in order to reach it, or the secret exit that is located in the top. If the player goes to the level's normal exit, the player will find a Giant Piranha Plant. After passing the Giant Piranha Plant the player can go to the right down path where the Mario Bros. can find two ? Blocks, one with a coin inside and the other with a Mushroom/Fire Flower inside and the top path where the level continues with another puzzle that in its left side contains the last Star Coin and to the right the player will find the level's exit, but before reach it the player needs to press a ! Switch to active some blocks in order to he finally reach the level's exit. The player can get the Trampoline at the end of the level to get an 1-Up if the player reaches the Flagpole's top.
 Secret Exit
When the player hits the orange switch, they will need to swim upwards into another room filled with Coins and Dash Coins. They will need to hit another switch, which will raise the water level once more. Taking the exit to the right will lead Mario or Luigi to a secret exit and access to World 2-A.
 Star Coins
 World 2-A
This level is the first and only bonus level in this world. Although this world is in the middle of a desert, this level is largely inhabited by water. The level is fairly monotonous, as opposed to most other levels in New Super Mario Bros.. This level features three types of enemies: Koopa Troopas, Koopa Paratroopas, and Spike Basses. The player must traverse across many platforms and utilize several Spin Blocks to proceed through the level. By using the Spin Blocks, the player can gain access to multiple hoards of coins hover in the sky. The player access the normal exit via the utilization of the green pipe - this pipe is located directly below the gold one. Once the player touches the Flagpole, the level ends.
 Secret Exit
Mario or Luigi will need to bounce off of the final spin block at the end of the level. With correct timing, they need to hop of the Koopa and into the gold pipe where the secret exit is found.
 Star Coins
 World 2-Cannon
This area, while not really a level, can be unlocked by using the secret exit in World 2-A. The area contains a cannon in the middle of the desert. If the player enters the cannon, he or she will be launched to World 5, which can be faintly seen in the background.
 World 2-Pipe
This pipe, only unlockable by completing World 2-A and using the normal exit, allows the player to gain access to the end of World 2. If the player does so, he or she can skip all levels in the world between 2-4 and 2-Castle. The pipe is just outside of the final castle in the world; thus, the player can enter the castle and complete the world, having skipped four levels (if none were played past the point of World 2-3).
 World 2-4
This level starts out with a seemingly flat desert surface. High in the air resides three ? Blocks and two brick blocks. At first glance, it seems impossible to reach the blocks alone; however, a few steps to the right there lies a ? Switch. By pressing this switch, the flat desert will quickly raise into the form of a steep hill, allowing the player to access the aforementioned blocks. After a few steps, the player will encounter a Goomba. Near the Goomba are six coins caged in by brick blocks. The player must ground-pound the bricks if he or she wishes to collect the coins. Past the first abyss, the player will find two Goombas and two Koopas. Surrounding the enemies are twelve blocks - four of which are ? Blocks containing coins, while the other eight are plain brick blocks. Past this point, the player will encounter another tiny abyss, followed by two Koopas and a Koopa Paratroopa. If the player stays on the lower ground level and continues rightward, he or she will see a warp pipe inhabited by a Piranha Plant. By wall jumping over the pipe, the player can collect a Star Coin. When the player heads up top and walks to the right, he or she will encounter a Koopa, a Goomba, and a downward staircase infested with Piranha Plants. The player can eliminate the plants with a single Koopa Shell At the bottom of the staircase is a shallow bed of water. To the left is a mini-pipe, able to accessed by using a Mini Mushroom. To the right are two more pipes with Piranha Plants. Another A P-Switch can be found on a small chunk of land. By pressing it, several Silver Coins will appear for the player to grab. Past here are two paths the player can take.
 Upward Path
By going up the staircase, the player will encounter a Goomba and three more Piranha Plants. Just past the Goomba is a small gap in the upper part of the wall. By wall jumping repeatedly, the player can collect several coins. As the player reaches the top of the stairs, a bridge with two Koopas can be found.
 Downward Path
A narrow path resides to the right underwater. At the end of the path are two pipes. By entering the red pipe, the player will be taken to a secret underwater area. In this area, several coins and two Cheep-Cheeps are found. In the opposite upper side of the area is a pipe. By using this pipe, the player will be taken underneath the aforementioned bridge. Another Star Coin can be found here. Then, by pressing the ? Switch, the ground will rise; the player can now walk atop the bridge and continue forth.
Farther right, a Paragoomba will be encountered. As the player continues, two blocks - one containing a ? Switch, the other containing a power-up - and a Piranha Plant are found. This is where the checkpoint is. By pressing the ? Switch, the ground beneath the Piranha Plant will rise. If the player rushes to the right - over another hill - he or she can gain access to a higher elevation, allowing access to the rest of the level. Past here are two Hammer Bros. guarding the final Star Coin. After here is a staircase with a Koopa, followed by the end-of-level flagpole.
 Secret Exit
Mario or Luigi will have to be mini to go to the secret exit. They will need to take the mini-pipe that is left of the upward and downwards path.
 Star Coins
 World 2-Tower
With the appearance of a few coins and a rotating platform, World 2-Tower begins. The player must jump to the first rotating platform, then to the next one. Above the second platform reside three ? Blocks - two containing coins, while the other contains a power-up. The player must then jump to the rotating platform located above the three ? Blocks. To the player's right is a Dry Bones that may walk upon the rotating platform. The player must then jump to the left, where another Dry Bones is located. Above here is a rope; the player must climb across the rope to a slightly higher location. Up even higher, another rotating platform will be found. If the player jumps to the left, he or she will land on a shallow cliff. From here, the player can repeatedly Wall Jump his or her way up to a door. Behind the door, there is a cluster of gold bricks in the shape of an "n". The player must then wall jump within the bricks nonstop as it rolls along the wire track. At the top, the player must drop out of the brick "n", quickly jump up the platforms, and land on top of the brick "n". The player can then jump to a new platform, nabbing a Star Coin along the way. The player must repeat the aforementioned process in the following brick "n" in order to access another door. The player will then drop into the main area.
If the player doesn't take the door's path, he or she can climb along a rope, activating a Red Ring along the way. Past here, a Spring is found; by utilizing it, the player can access the pipe located directly above. In the next area, the checkpoint is activated directly before a ? Block. As the player jumps across several rotating blocks, he or she will encounter two Dry Bones directly beneath a red pipe. On the other end of the red pipe is a door; and behind that, Bowser Jr. awaits. The battle with Bowser Jr. is the same as the previous one - only this time, the player must avoid falling in quicksand.
 Star Coins
 World 2-5
The player will start off in the desert. They will see two ? Blocks on the ground, which will contain coins. The next ? Block will contain a power-up. The player will now see many Brick Blocks on top of ? Blocks which also contain coins. The player will now encounter their first Blockhopper, and will see a lone ? Block containing a coin. The Blockhopper will contain a power-up if defeated. As the player advances, they will find more Brick Blocks and ? Blocks, all containing coins. The player will see a Spiny here, and some more Blockhoppers. This time, the Blockhoppers will contain coins. If the player jumps on top of a blockhopper, they can reach some coins as well as their first Star Coin throughout the level. All the Brick Blocks here will contain a coin. The player will climb ontop of some rocks, and will find another lone Blockhopper here, as well as some coins. Jump ontop of a Blockhopper to reach the coins if necessary. The player will find another Blockhopper, which will help the player reach more coins, and another Blockhopper beside this one, which will contain a power-up if defeated. The player will advance, and find some coins with a lone ? Block containing a power-up. A Fire Snake along with another Blockhopper with a coin can be seen here. The player will have to jump to cross the gap, and will find another Fire Snake surrounded by Blockhoppers containing coins.
Many coins will be seen in the air, and the player will find 3 Brick Blocks; with one containing a P-Switch. The player will have to jump from a Blockhopper to reach the P-Switch, and after the player presses it, a path to leading to the second Star Coin will appear. As the player advances, they will find a moving platform that will go vertically. A Boomerang Bro. can also be found here. The player can now take two routes. The first route is to take the pipe guarded by the lone Boomerang Bro., which will lead to the last area in this level, and the player will find a lone Blockhopper and the Flagpole. The player should jump off the Blockhopper to reach the top of the Flagpole. Or, if the player wants to take the other route, they can go under the quicksand from the area before, and keep jumping to avoid being sucked in, to find a block that the player will be able to go through, which will lead to some more blocks the last area, and some more blocks the player can go through. The player should fall down from the blocks, and jump across the gap to find many coins, a lone Blockhopper, and a Star Coin. The player should use the Blockhopper to get everything in this section of the area. The player will then jump from the blocks that they could go through and will end up by the pipe the player would have came from if they took the first route, and will follow the same route to reach the end of the level. The player will now have access to World 2-6.
 Star Coins
 World 2-6
This level starts out with a pit full of quicksand; buried within it as a gold pipe in the shape of an "n". The player must hop across the quicksand and the gold pipe in order to make it to the other side of the pit. On the other side of the pit, two ? Blocks can be found, followed by a red pipe. The player must enter this pipe to continue. On the exiting end of the pipe, the player will appear on a levitating platform; the moment the player touches said platform, it will begin to move rightward. As the player continues forth in the level, he or she will encounter several coins, some of which are surrounding three ? Blocks. Slightly further in the level, the player will begin to encounter a few Piranha Plants; these Piranha Plants are located each on a separate levitating platform that intersect with the platform the player resides on. Eventually, Piranha Plants will be placed on the same platform as the player, providing an additional challenge to the level. More ? Blocks can be found throughout the level - some containing coins, others containing power-ups. As the level progresses, more Piranha Plants and a Giant Piranha Plant are encountered. Eventually, the player will have to jump off of the original platform, and hop on smaller levitating platforms. When the player encounters a Venus Fire Trap, there are only a few more levitating platforms to jump on before solid ground can be reached. On this solid ground, the player will have to use a pump to unblock a green pipe, which was blocked by a cork. On the exiting end of the pipe, three more levitating platforms and a Piranha Plant are located, followed by the flagpole.
 Star Coins
 World 2-Castle
This level is the final level of World 2. The level starts out with the player standing beneath a shallow stairway of brick blocks; these brick blocks are almost immediately pulverized by an enormous rolling ball of spikes. This spike ball will manage to avoid the first abyss, rolling shortly on the next platform; however, it quickly rolls back into the abyss. The player can now safely jump across the first abyss, nabbing three coins along the way. The player will find a ? Block with a coin inside right next to three more coins over the next abyss. The player can collect these as he or she jumps across the second abyss. Past here, the player will encounter many more of the spiked balls, though they vary in size. The player can find yet another ? Block containing a power-up - this can be useful when having to avoid the many obstacles of this level. Eventually, the player will see a divot that contains a massive spiked ball, ricocheting off of the walls as it rolls back and forth. Above this spiked ball is a rope. The player can grab a hold of this rope and swing over the divot to avoid danger. By swinging and landing low, the player will collect six coins and continue forth in the level; by swinging and landing high, the player will gain access to a previously-unseen group of platforms. These platforms host about thirty coins, and a ? Block containing a 1-Up Mushroom. Farther to the right, the player will see three more ? Blocks - two containing coins, the third containing a power-up. Past here, the player will have to crouch down into several small divots to avoid being harmed by roving spiked balls. The player will eventually see a Star Coin that must be accessed via the use of a few Wall Jumps, while avoiding yet another spiked ball. On the opposite side of the abyss, the player will encounter another spiked ball, followed by a door leading to the outside world.
In the outer sanctum of this castle, the player will encounter a great abundance of Bullet Bills and spiked balls. He or she must avoid multiple obstacles and traps to make it to the other side of the grounds, where access to the inside of the castle can be gained once again. The last two Star Coins can be received out here - one must be retrieved by jumping on a Bullet Bill to reach a high crevice, while the other can only be accessed via the use of a Mini Mushroom. At the end of the grounds, the player must press a ? Switch which lowers the ground, allowing access to the door that leads to Mummipokey.
Once the player defeats Mummipokey, the player will gain access to a new world. If Mummipokey is defeated while Mario or Luigi are in a miniaturized state, they will gain access to World 4. If Mummipokey is defeated by any other means, the player will gain access to World 3.
 Star Coins
 Enemies introduced