World 1 (New Super Mario Bros. Wii)

The Mushroom Plains of New Super Mario Bros. Wii has six levels, and a Grand Goomba who roams the map. Larry Koopa is the first boss to be fought in the game. This world features typical grassy plains and many different environments similar to New Super Mario Bros. and the first world in other games.

1-1 (The Grassy Plains)
The first level of the game is a generic grassland level. In the beginning of the stage just like in New Super Mario Bros., Princess Peach's Castle can be seen in the background. When the player starts, there are three ? Blocks, a few normal blocks, and a Goomba. The highest ? Block will hold an item, either a Mushroom or a Propeller Mushroom. The player must move to the right and they will see a moving piece of ground. Then move farther ahead and another moving piece of ground will be there. It has three platforms above it. It has a Green Pipe in it that moves around with it. Jump in it. In the underground area there are blocks, coins, and a P Switches. The player should hit the P Switch and collect the coins that were blocks. The P switch will lose its effect and the player can collect the remaining coins and head out the yellow pipe. If they are playing a Toad Rescue Mission a Toad should be yelling out from the ? Block behind them. The player can head forward to find their first checkpoint. Then they should hit the ? Block to get a Propeller Mushroom and get the Star Coin in the air. Go past the two pieces of moving ground and hit the second ? Block for another item. Spin upwards using the Propeller Mushroom and go through the Red Ring. Collect the Red Coins and continue forward. At the end of the platform spin to the next one and then skip the next one with the red Koopa and collect another Star Coin. Jump off the left side of the platform and find the moving piece of ground. Wait for the Green Pipe and jump in it. Alternatively, the player could stay in the "compartment" and get three 1-Ups and dozens of coins. If the player went in the pipe, wall kick up, collect the last Star Coin and head out the yellow pipe. The player will be in a hidden area. Just before leaving the hidden area there is a block, hit it and collect the 1-Up Mushroom. Continue forward and complete the level.

1-2 (Creepy Cave)
This level takes place in underground. Special power-ups and items include Ice Flowers, Fire Flowers and POW Blocks are used there. Right about where the halfway point is, there is a way to get infinite 1-ups. The player must jump into a cave, grab a star, and kill all the Koopa Troopa s and Pirahna Plant s in their path.

1-3 (Yoshi Heights)
This is the first stage to feature Yoshi, along with the Hammer Bros. The first Star Coin is located a tiny bit after the player finds Yoshi. The best way to get it was to flutter jump off the ground with Yoshi, or just to dash and jump to the coin. The second coin is found deeper in the level, where there will be three green pipes with Piranha Plants. Next to the third pipe will be a hidden passage, where this pipe leads down to a underground tunnel. The coin will be found there. The last star coin is near the end, way too high for Mario, Luigi, Blue Toad, or Yellow Toad to just jump up. The player should do one of the following opinions: use Yoshi to flutter jump off the nearby pipe, jump with Yoshi under the coin and shake off of him, or wall jump off the nearby pipe mentioned before. The player must then continue down the course until he/she reaches the flagpole and completes the level.

For the secret entrance, the player should go back just a tad bit before the last star coin. The player needs to jump to the high cliff edge leading to a hidden passage. Using Yoshi is the best. Once the player reaches the entrance point, he/she needs to jump over the passage, above the screen, and travel down the path following it. Near the end of this path will be a secret pipe, which will send the player to the secret flagpole. The secret exit will take the player to World 1's warp cannon, which sends him/her to World 5.

World 1 Fortress (Larry's Tower)
This is the first stage where Larry Koopa is fought and defeated. At the beginning of the level there is a rising brown platform which brings Mario up and lets him hit a ? Block which releases an Ice Flower. The flower will change Mario into Ice Mario allowing him to throw snowballs. There is also a Dry Bones in this area. In the next area there is another rising brown platform for Mario to stand on which will lift him to the first of many swinging platforms. The swinging platforms go back and forth allowing Mario to jump off of one of the two sides. Mario must use this one to jump on to another platform which has two extending brown blocks from the wall which create a staircase for a few moments that Mario must jump up. The next area has another swinging platform with two different ways for Mario to go. The first is the easy way with two platforms and a Dry Bones at the top and the second is the hard way with an extending platform and a Star Coin (Plus multiple regular Coins). In the next area there are three platforms in a line that Mario has to jump up with Dry Bones coming on from the sides. There is once again a fork which forces Mario to either tale the easy way which has several moving platforms creating another staircase or the hard one with multiple immobile platforms for Mario to jump up. At the top of this area is the Bowser Flag.

The next area has a multitude of brown platforms going in and out of the walls creating a staircase for a few seconds before they come together and crush Mario if he is in between them. There is a block with multiple Power-Ups (Propeller Mushroom, Starman, Starman, 1-Up Mushroom and Mushroom) followed by another swinging platform leading to a fork. Once again the easy path takes Mario to another (dual) swinging platform and the hard one takes him to a prize; in this case a 1-Up Mushroom. If he takes the easy path and is Small Mario then he can slip through a hole and get the final star coin. The next area is a combination of five swinging platforms with the Red Ring and the Red Coins. To get to the top, and to the door that leads to Larry, Mario must use the extending brown platforms. When Mario goes through the door that leads to Larry Koopa, Larry will be in the middle of the room. He will see Mario and jump in surprise but then he will attack. Larry attacks by blasting bolts of blue magic from his Magic Scepter at Mario in an attempt to hit him. Mario must dodge those attacks and get close enough to Larry to jump on his head therefore making him lose a life. Larry will then get into his shell and start spinning around madly trying to hit Mario. He will then try to jump on Mario so Mario must avoid him. If Mario dodges these two attacks then Larry will start shooting magical blasts again and Mario can jump on his head again. Jumping on Larry's head three times defeats him and wins Mario the level.

1-4 (Lake Diving)
This is the first Underwater level in the game. Cheep Cheeps, Urchins, Mega Cheep-Cheeps, Deep Cheeps, Clams, and Spiny Cheep Cheeps appear. At the beginning there are two Cheep-Cheeps that must be frozen so that Mario can get to the ? Block, which will get him an Ice Flower. There are many bubbles flying around that can push Mario into walls.

The next area also has Deep-Cheeps which must be frozen along with the Cheep-Cheeps. There is also another ? Block with another Ice Flower in case Mario has lost his previous one. On the land there is a Red Ring which will make lots of Red Coins for Mario to collect. There is also a checkpoint flag.

In the next area there is a roof so Mario must freeze the Urchin and it will break the roof allowing Mario to get through. There is also a Star Coin which is guarded by a Mega Cheep-Cheep that Mario must freeze to get past. In the next area there is a room which has a Spiny Cheep-Cheep that will follow Mario. He must destroy that Cheep-Cheep and then get the 1-Up Mushroom at the bottom of the screen. There is also a Fire Flower and a Starman. Mario must then go through a Red Pipe. Many Cheep-Cheeps populate the next area so Mario has to use his Starman to destroy as many as possible and then go through the green pipe. Then there is a Koopa Paratroopa that Mario can use to land on the flag at the end of the level.

Enemy Course

 * Eight Goombas
 * Four Grand Goombas
 * Two Mega Goombas

1-5 (Mushroom Heights)
This is the first sky level. It mainly features cube (square) platforms that rotate in one direction.

1-6 (Donut Plains)
This level is called donuts because of the many donut shaped pieces of land there is here. At the beginning, the player must jump over all the donuts at the halfway point, there is a donut. If players jump to the wall on the left, there is a secret pipe that takes them to an underground cave with a star coin. Players will then navigate through a maze of Pirahna Plants and donuts.

World 1-Castle (Larry's Castle)
This is the first Castle level, filled with a lot of lava in the game and features many gear-shaped platforms. Thwomps and Super Thwomps make their only main appearance in this castle.

Larry Koopa is fought again here.

Enemies Introduced

 * Goombas
 * Koopa Troopas
 * Koopa Paratroopas
 * Piranha Plants
 * Venus Fire Traps
 * Hammer Bros.
 * Dry Bones
 * Cheep Cheeps
 * Mega Cheep-Cheeps
 * Spiny Cheep Cheeps
 * Deep Cheeps
 * Mega Deep Cheeps
 * Cheep Cheep Schools
 * Clams
 * Grand Goombas
 * Thwomps
 * Super Thwomps
 * Podoboos