World 6-3 (New Super Mario Bros. Wii)

In this level, there are Big Piranha Plants, Stalking Piranha Plants, and Buzzy Beetles. The course is a network of Warp Pipes with raising and lowering platforms which the Big Piranha Plants are on top of. Some switches raise and lower the level of the water.

Layout
The level starts on an horizontal warp pipe, in front of two other, vertical warp pipes, with one accessible and the other one having a Piranha Plant hiding inside. Once the correct warp pipe entered, the player(s) will fall from the top of the screen, landing by a Switch and, on the other side, a big Piranha Plant. Once the switch hit, it will cause water to raise from off-screen, allowing the characters to go up and get out of the pit they were standing in. The following path is a narrow diagonal path with Buzzy Beetles in it. After that, another big Piranha Plant is on the way, and has a Question Block above it, which contains a Fire Flower. Then, after another narrow path awaits a third big Piranha Plant, above of which is the first Star Coin. Then, they will have to come across a large room with a switch similar to the previous. It will, like the other one, make water rise from off-screen, and if the player wants the Star Coin they must swim in the passage under the main one in which is a Big Piranha Plant. The player will then find a checkpoint in a chamber overrun with Buzzy Beetles on the ground and ceiling, and will then arrive somewhere with lots of Piranha Plants with two sets of Brick Blocks; the player will have to wall jump above these blocks to get to the last Star Coin. The last room consists of multiple other big Piranha Plants, another switch on the upper part of the room, and the exit. To get there, Mario must simply go to the upper part of the room, press the switch to make water rise again, and take this as an advantage by going through the exit, all with a little speed. Before the Flagpole is a staircase made out of pipes, from which Piranha Plants randomly pop out of.

Star Coins

 * Star Coin 1: The first Star Coin is floating above the third Big Piranha Plant. Mario and co. must kill the Big Piranha Plant and then use the platform to rise up to it, or wall kick.
 * Star Coin 2 (pictured): The second Star Coin is next to the fourth Big Piranha Plant. Mario and co. should again kill the Big Piranha Plant to make the Star Coin accessible.
 * Star Coin 3: At least a Super Mushroom is required for this one. Shortly after the Checkpoint Flag, there are three Big Piranha Plants with one guarding a row of Brick Blocks. Mario and co. must break through any but all of the Brick Blocks and wall kick to the area atop them to be brought to the secret area with the third Star Coin.

Enemies

 * Piranha Plants
 * Big Piranha Plants
 * Stalking Piranha Plants
 * Buzzy Beetles