New Super Mario Bros./World 1

World 1-1
The first level of the game. There is a Mega Mushrooms in the first ? Block after the first pipe. To make best use of it, kill the Goomba to its right, then hit the block and follow the Mega Mushroom rightward. Shortly before when the shroom would fall into the pit, grab it! Now run to the right as fast as possible. You will need to jump once onto a hill. Doing so, you should be able to reach the flagpole as Mega Mario and take the maximum possible five 1-Ups!

Stand under the ? block with the Mega Mushroom, then hit it at the timer 362. Follow the shroom to the pit and run right as before; you should smash the flagpole at time 333 and make a red Toad House. Hit the block at time 328 to smash the flagpole at time 299 and make a mega Toad House, which allows you to take a Mega Mushroom to another course!

The first Star coin is just after the second pipe. Jump on to the pipe, then jump on the bricks to get it. For the next Star Coin, jump down the third pipe (Stand on the pipe and press down). This will lead you to an underground area. The Star Coin is at the end of this. Jump on the pipe to get it. The last Star Coin is under some bricks. If you went through the underground area for the second coin you'll have to go back to get it. Stand on the bricks, jump and when you are in the air press down to Ground Pound for the Coin.

World 1-2
This level takes place in underground. Near the start of the level you'll see coins under some bricks. You can get these by Ground Pounding the bricks. The third one when Ground Pounded all the way down will lead you to a room with 31 coins. Continue right and you will see the first Star Coin for the level. Jump on the bricks to get up to it. The next star coin is under some bricks later in the level. Ground Pound them to get it. The first pipe after the half way mark leads to a hidden room. Inside this room is a Koopa. If you jump on the Koopa and get him to break all the bricks under the pipe, it is possible to run along this passageway. This is easier to do if you are regular Mario, but can be done if you are big by running towards the passageway and pressing down to slide under. This passage leads to another hidden room full of Gumbas. At the far end of the room is a ? block which contains a Mega Mushroom. Just before the end of the level, use the sea-saw to jump up to the ceiling and run along it pastry the pipe. This will lead to a hidden room where the last Star Coin. The pipe leads to an alternative exit which opens up a hidden path past World 1-3.

World 1-3
Go right until you get to the first Spin Block. Use it to jump up to the platform above. There you'll see another spin block, use it to jump up to yet another platform where the first Star Coin is located. You should be able to see a trail of coins to the right. Follow this trail down and it will lead you to the second Star Coin. The third Star Coin is just after the half way point.

World 1-Fortress
In the begining, there are two ? blocks and a dry bones. The left ? contains an item while the other has a coin. In this fortress, there are a lot of blocks that come in and out, so don't get squished. Just keep climbing until you get to a part where the blocks change direction. Just wait until the bottom block goes down to run across. Above these blocks is the first Star Coin and an item. Climb up the stair blocks until you get to a pipe and a black door. If you want to get the Star Coin, go up the right side. After climbing up, go to the left and fall through the dotted coins to the yellow door. Inside is a room filled with tons of moving blocks going all different directions. Climb across the room to the third and final Star Coin. Once you get it, DON'T GO IN THE DOOR! Jump up to the slow moving block and walk to the right. You will enter a secret room with a yellow pipe. If you have Turtle Shell Mario, go to the right until you see the small blocks. Break them to get to a secret end of the level that leads to a cannon. If you didn't have Turtle Shell Mario, just go up the pipe. Once here, be carefull launching yourself out of the pipe. If you don't do it at the right time, you might get crushed. Once at the top, go into the door to fight Baby Bowser. Just jump on him a few times to defeat him.

World 1-Cannon
If you were able to make it out of the secret path in the castle, you will be sent to a cannon that will launch you into World 5. If this is your first time playing through the game, I advise you not to play the levels here yet.