Wario is reading the newspaper when he notices an article about a mysterious pyramid found deep in the jungle. The legend related to the pyramid is that of Princess Shokora, ruler of the pyramid, who was cursed by the money-crazed Golden Diva.
Without wasting time, Wario jumps into his Wario Car and drives to the pyramid. As he enters it, he finds a black cat and chases it. Doing so, he falls down a precipice and is stuck inside the pyramid.
After fighting his way through the entry passage and an early boss battle against Spoiled Rotten, Wario discovers four new passages. After completing these passages, Wario gains access to the innermost part of the pyramid, which ends up being the stronghold of Golden Diva. Wario meets the cat again, who turns out to be Princess Shokora.
Wario defeats Golden Diva and exits the pyramid with all his treasure. What form Shokora returns to depends on the number of treasure chests Wario had acquired from the other bosses prior as well as how quickly the Golden Diva is defeated (this can range from a brattish child, a female version of Wario, a Peach-like princess and ultimately, a superheroine-like princess). Shokora gives Wario a kiss on the cheek and ascends to the afterlife.
Wario jumps between platforms on the Monsoon Jungle level of the Emerald Passage. Ahead of him lie four blue crystals; behind him, an enemy crocodile has jumped out of the water in an attempt to bite him.
The gameplay of Wario Land 4 (which is generally similar to that of Wario Lands 2 and 3) allows for some open-endedness as well as some order of difficulty. After an Entry Passage that serves as a tutorial for the game, there are four main passages: the Emerald, Topaz, Ruby, and Sapphire Passages, in order of difficulty. The Emerald Passage is themed around nature. The Topaz Passage is themed around toys, games, and other “playtime” ideas. The Ruby Passage is themed around mechanics and technology. The Sapphire Passage is themed around horror and danger, prominently involving ghosts and the like. After these four main passages is the “Final” Golden Pyramid, which serves as a recap of these four themes and also houses the Golden Passage level and the final boss.
Wario’s objective in each of the 18 levels is to find the room’s treasures and escape the level with them. The room’s treasures include:
Four gem pieces, which unlock the door to the boss (all gem pieces in all four levels must be collected)
A Keyzer, which allows access to the next stage
A music CD, which unlocks bonus music in the Music room (not found in the Entry or Golden passages)
Many coins and gems