World 1-4 (New Super Mario Bros. Wii)

World 1-4 is the first underwater stage of New Super Mario Bros. Wii and the fifth overall level of World 1. This level introduces Cheep Cheeps, Deep Cheeps, Eep Cheeps, and three other underwater enemies. It is unlocked by completing, and its own completion unlocks World 1-5 and World 1-6, along with an Enemy Course and a Red Toad House. This is the first level to feature the Underwater Theme, which plays throughout the underwater sections.

Layout
At the level's start, there are two ? Blocks, two Goombas, and a Warp Pipe leading underwater. After the player descends, there are two Cheep Cheeps that can be frozen so Mario can get to a ? Block, which contains an Ice Flower. There are multiple Pipes that shoot bubbles around the level that can push Mario into walls or enemies.

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. Past here, there is a Red Ring in a secret area on top of the stage, which makes eight Red Coins visible for Mario to collect, along with the level's midway point.

In the next area, the road is blocked by an Urchin, which Mario must freeze to get through. There is also a Star Coin guarded by a Big Cheep Cheep that Mario must freeze. As Mario continues on, there is another Star Coin guarded by two Pipes that generate a current that keeps the player from getting too close. The Star Coin can be collected if the player freezes a passing Cheep Cheep and stands at the top of it as it floats up, fighting the current. The final Star Coin is a short distance forward, where an Urchin must be frozen to block the current and allow the player to pass and collect the coin. In the next area, there is a Spiny Cheep Cheep that follows Mario. After destroying the Cheep Cheep, Mario can get a 1-Up Mushroom at the bottom of the screen. There is also a Fire Flower and a Star in the nearby ? Blocks. Mario must then go through a red Warp Pipe. Many Cheep Cheeps populate the next area, but Mario can use the Star to destroy as many as possible. After escaping from two Spiny Cheep Cheeps, Mario can take a green Warp Pipe back to the surface. There is a Koopa Paratroopa that Mario can use to reach the top of the level's flagpole.

Star Coins
An Ice Flower is required for all three Star Coins.
 * Star Coin 1: The first Star Coin is floating above a wind-blowing red Warp Pipe, just after the midway point. Mario and co. must freeze the nearby Cheep Cheep and use it to get on top of the Pipe and get the Star Coin.
 * Star Coin 2: Not too far from the first Star Coin, the second Star Coin is floating high up between two wind-blowing Red Pipes. Mario and co. must freeze a passing Cheep Cheep and get on top of it at the right time to float up to the Star Coin without getting blown away by the wind.
 * Star Coin 3: Shortly after the second Star Coin, the third Star Coin is located directly under a Clampy, and to the left of two Pipes (one of them blowing wind) and an Urchin. Mario and co. must freeze the Urchin so it will fall onto the wind-blowing Pipe and make the Star Coin accessible.