Wario Land 3: Part 59: The Stagnant Swamp (Green Chest)

First off, go into the same room where you get chased by the Robo-Mouse, then get chased by it again. At 0:37, use the High Jump Boots to reach the doorway above. In the next room, keep high‑jumping off enemies to climb higher, taking one of the two enemies at the bottom with you while bouncing off the others to reach the last platform that holds the Green Key. Return to the Robo‑Mouse room, climb to the Red Key, high‑jump to the warp pipe, and prepare for a boss battle. The boss is a pirate ghost named Jamano; if he grabs you, he’ll kick you out. To defeat him, bash away the ghostly skulls blocking the lights, and when you kill him, his hat leads you to the Green Chest. The Stagnant Swamp’s Green Chest Treasure is the 4th music box, creating a new stage called Beneath the Waves.