World 2-4 is a desert level in New Super Mario Bros..
At the beginning of the level, Mario will find a ? Switch, a Goomba, and several coins and blocks. If he hits the ? Switch, the sand will rise temporarily, making it possible for him to hit the blocks high up in the air. Just after this, there is a pit, and an area with many blocks and several enemies, both Koopa Troopas and Goombas. After this area, there is a Koopa Paratroopa guarding the first Star Coin. There is a Piranha Plant in the area of the Star Coin, and a green Koopa Troopa will wander into the area, so Mario should avoid those. There is also a red Koopa Troopa, but Mario does not need to worry about that as much because it cannot walk off ledges. Mario will then enter a very steep passage with Goombas and Piranha Plants in it. There is also a mini Warp Pipe near here. This mini pipe leads to the secret exit. In order to proceed, Mario should continue right. There is also a P-Switch here. If it is hit, many Silver Coins will appear. Then, there are two different paths.
In order to go on the lower path, Mario should swim down under the ground, but high enough to keep him from drowning. Next, he should avoid the Piranha Plant and enter the red pipe. This will take Mario to an underwater area inhabited by Cheep-Cheeps. One of the Cheeps has several coins behind it. To get back up to the surface, Mario should enter the red pipe to the right. When he does this, he will come out in an aboveground area with the first Star Coin. Then, he should hit the ? Switch, and jump on top of a bridge. He will then find a Paragoomba, and a more open desert area with blocks in it, and the Midway Point. Then Mario will find a Super Piranha Plant. Mario should then hit a block, and another ? Switch. Pressing this switch will raise the sand, making it possible for Mario to proceed. Mario will then encounter some Hammer Bros., who are guarding the final Star Coin. Then Mario will find a red Koopa Troopa, a pit, a green Koopa Troopa, and the exit.
In order to go on the upper path, Mario should go up, and avoid the Piranha Plants and Goombas. He can also wall Jump up a small area to grab several coins. Then, he will find a bridge, and he should continue on the same way as the lower path.
- Star Coin 1: In a small underground area, on top of a green Warp Pipe. Watch out for a Piranha Plant in the pipe and also a green Koopa Troopa.
- Star Coin 2: In the P Switch area, you can swim under the map to the right. This will take you to an area with a green and a red pipe. Go down the red pipe and you will be in an underwater cave. Swim to the end and go in the red Warp Pipe. This will take you to an area back in the desert where the Star Coin is. Don't press the ? Switch because the sand will block the Star Coin.
- Star Coin 3: There will be an area with two rows of Brick Blocks. The Star Coin will be in between the two rows. Watch out for the Hammer Bros.