The Stagnant Swamp

The Stagnant Swamp is the first level on the eastern side of the music box world in Wario Land 3. It is unlocked after getting the Ornamental Fan in The Pool of Rain's Green Chest, which blows a gust of wind to extinguish a misty barrier that obstructs the way to the eastern side of the world.

This level is a swamp where there are a lot of ziplines above the surface, while there are trees in enclosed areas behind the doors found above the swamp and under it. This is also the only level in the game with two bosses: Muddee is found below the Warp Pipes above the swamp, while Jamano is above the woods. The latter is required to be defeated to obtain one of the music box, namely the fourth one.

Gray Chest: Flute
The Flute is in the Gray Chest. It is available as soon as the level is unlocked.

The Gray Key is found under the swamp, accessible by going down the ladder. It is accessed by using the slope found there to roll to the middle, where the Gray Key is.

After obtaining the Gray Key, Wario must make his way back to the beginning of the level to ride the zipline handles. In particular, Wario must go to zipline handle located at the upper right that travels down and to the right, which allows him to roll through the tree trunk to access the Gray Chest.

The Flute summons snakes in The Peaceful Village, The Grasslands and The Volcano's Base, allowing Wario to reach higher places in those locations from the heads of the snakes.

Red Chest: Green Flower
The Green Flower is in the Red Chest. It requires the Foot of Stone from The Tidal Coast's Red Chest, which causes the swamp's water level to lower, revealing two pipes and a door in between them.

The Red Key is within the door in the middle, where there is a Robo-Mouse pursuing Wario. To get to the key, Wario must break his way through the tree trunks to the right, and then at the end, go up to a higher level, and then go left. There are Spear-bots patrolling the upper level. The Red Key is located near the Warp Pipe, which can be collected even though the pipe can't be entered currently.

After obtaining the Red Key, Wario must exit the area through the door to the left, and then go to the right Warp Pipe from the door down. After exiting the pipe, there will be a turtle that can be ridden on. While riding the turtle, it will stop below the wooden grillage, after which Muddee, the boss of this area, appears. In order to hit Muddee, Wario must use a Smash Attack while it is under him unless its spiky tail is below him. If Wario touches the spiky tail, Wario will flinch and fall into the water current, where he must reenter the area through the pipe to start the battle again. Muddee initially moves orthogonally to pursue Wario, but in its third phase, Muddee will pursue Wario directly by moving diagonally. After Muddee is hit three times, it will be defeated and the turtle will reappear, allowing Wario to ride it to reach the Red Chest.

The Green Flower, along with both the blue Tusk in The Volcano's Base's Blue Chest and the red Tusk in The Steep Canyon's Red Chest, causes both The Colossal Hole and The West Crater to become accessible as a result of the volcano's eruption due to the gathering of the three treasures.

Green Chest: Red Music Box
The Red Music Box, the fourth of five music boxes, is in the Green Chest. The High Jump Boots in The Colossal Hole's Green Chest is required, in order to reach platforms that lead to where the key and chest are.

To get to the Green Key, Wario must first go to the room above the swamp where the Robo-Mouse is. On the way to the right, there is a platform where a Musical Coin. A door is above this Musical Coin. Within this room, there are Para-Gooms, Spearheads, and a Spear-bot. On the ground, either the Para-Goom or the Spearhead must be carried, and then use the other to bounce to the platform above. After bouncing off the Spear-bot, then the enemy needs to be placed on the platform to bounce off from. The Green Key is within reach on the highest platform in this room.

After acquiring the Green Key, Wario must exit the room and then go right, up, and then left to where the Red Key is. With the High Jump Boots, Wario can access the pipe next to it, which leads to the boss room with Jamano, who starts the battle in a dim room. To defeat it, Wario must remove the skulls from the four corners of the room with Dash Attacks to light up the room. Each skull will respawn after 5 seconds and return to position in another 3 seconds. If the boss grabs Wario, Wario will be ejected from the room to the swamp outside, requiring the battle to be fought again. If all four skulls are removed and the room is fully lit, the boss is defeated, and then its hat will become a floating platform to which Wario can stand on to reach the Green Chest.

After being played, the Red Music Box causes a whirlpool to appear in the western sea, unlocking Beneath the Waves.

Blue Chest: Eye of the Storm
To get the Eye of the Storm from the Blue Chest, the Explosive Plunger Box from Beneath the Waves' Gray Chest is required, where it causes the bombs to detonate and break the floors that they are attached to.

The Blue Key and Blue Chest are located in the room under the swamp, which is located at the right side of the stage down the ladder. The door is tucked away behind the wall and the tree trunk. The Blue Key is past the first set of tree trunks in the air, which requires using one of the Pneumo in the lower level to trigger Puffy Wario to allow Wario to reach it. The tree trunks below the Pneumo are required to free them so that they can poke Wario.

After acquiring the Blue Key, Wario must go past the second set of tree trunks, and be at the lower level to lure a Pneumo there to trigger Puffy Wario and float upwards. To the right near the top, there is a spike that must be avoided. Once Wario lands to the right of the spike, he must break past the tree trunks to the right to reach the Blue Chest.

The Eye of the Storm, along with the Pouch from Cave of Flames' Green Chest, causes a strong wind to blow from the pouch after the former is inserted into the latter, causing a suppression in the pouch that releases wind from it. It makes leaves fall in Out of the Woods, therefore enabling them to be used as platforms.

Enemies

 * Spear-bot (6)
 * Spearhead (4)
 * Para-Goom (2)
 * Pneumo (2)
 * Beam Robota (1)
 * Robo-Mouse

Reaction abilities in this level

 * Puffy Wario (via Pneumo)