World 4 (New Super Mario Bros. Wii)

World 4 is the name of the fourth world of in the game, New Super Mario Bros. Wii. It is on several tropical islands, therefore, most of its levels are water themed and have a rather good use on the Penguin Suit, which can glide over water and allow Mario to swim better. Also, on the map is a bridge surrounded by a Porcu-Puffer that can jump up and make Mario and the gang endure an Enemy Course. This is also the first world to have a level on an Airship, like there was in Super Mario Bros. 3.

World 4-1
This level has two choices right from the start- platforms or water. The player can clear the level by jumping on platforms or totally be in the water. This level has Urchins, Mega Urchins, Cheep-Cheeps, Spiny Cheep-Cheeps, and more.

World 4-2
A lot of this course is filled with Donut Blocks and Cheep-Cheeps that will jump up to attack the player. To get one of the Star Coins, Mario has to stand on a long falling platform with the Donut Blocks' coloration.

World 4-3
This is the only level that features Huckit Crabs. There are a lot of Mega Urchins. This is one of the few levels where a Mini Mushroom is found.

World 4-Fortress
This tower features a lot of conveyor belts. Metallic blocks are also a common sight here; some are needed to advance, while others are more of a nuisance. If the player isn't careful, he/she may get crushed by the blocks. Wendy O. Koopa is fought here in the end.

When the player gets to the room where the metallic blocks form a staircase, they can run across and enter a wall with a darker coloration to find a secret pipe to the secret exit which unlocks the cannon to world 6.

World 4-4
This is an underwater level. It is infested with Bloopers, Blooper Nannies and pipes that blow bubbles. There is a secret area that where the player can get a Starman and another one where there is a Penguin Suit and the second Star Coin. The last one is inside a wall near the end of the underwater section.

World 4-Ghost House
The first part of the level, the floor moves up and down (right at the beginning there is a Starman) and a secret exit that takes the player to the castle and a Starman house. The rest of the level is infested with little mousers and possessed furniture.

World 4-5
This level is on a beach filled with Lakitus and cloud blocks (when the player hits them they turn into Lakitus that throw coins instead of Spinies). At the beginning the player can find a Yoshi to make the level a bit easier.

World 4-Castle
This course features fences that can be held onto, along with some Koopa Troopas that are on the fences as well. The player can also change which side of the fences he/she can hang on from.

Additionally, the spiked pillars that appeared in Wendy's Castle and the Valley Fortress back in Super Mario World make an appearance here. However, they're all horizontal instead of vertical.

Fishbones make their first appearance in this game here.

The player faces Wendy O. Koopa for a second time here. However, at times the water level will rise, which can make it harder for the player to stomp on her head.

There's a glitch in this castle that allows the player to gain infinite Coins and a large number of 1-Ups. They need at least two players (or one solo with two characters), one of them with an Ice Flowers. When the player enters the Castle, past the first Spike Pit, in between the first and second pits, he/she goes in a target area. The target is the Koopa with the Gate, but the Koopa must not be attacked. The player with the Ice Flower should stand on top of the right ? Block (on the backside of the Gates), and the other on the front side gate. When the Koopa is on the other side of the gate, they must Freeze and hit the cage at the same time. If done right, the Ice block will fall (with the Koopa moving around it) and two never-ending streams of Coins fly out.

World 4-Ship
This is the first airship level in the game. The main obstacle in this level are the Mecha-Koopas and the rocket engines. There is a pipe where Mario will find screws. Near the end, there are pipes that shoot out Bob-ombs. The boss of the airship is Bowser Jr. in a Koopa Clown Car.

Enemies Introduced

 * Mega Urchins
 * Porcu-Puffers
 * Huckit Crabs
 * Bloopers
 * Baby Bloopers
 * Blooper Nannies
 * Cheep-Chomps
 * Little Mousers
 * Fishbones
 * Mecha Koopas
 * Rocket Engines