The Tidal Coast

The Tidal Coast is the fifth level on the northern side of the music box world in Wario Land 3. After the music box in A Town in Chaos' Red Chest is collected and its tune played, this level is unlocked alongside Bank of the Wild River.

The Tidal Coast takes place in a craggy area directly at the coast. Most of the level is flooded, and the only dry spaces are atop of rock formations. Several caves can be accessed from the flooded area, including an underwater cave inhabited by Octohōn, another submerged cave filled with air bubbles, and a cave full of grillage and spikes. The water level is different between day and night, where it is two blocks higher at night, which causes one of the caves to be accessible due to a block floating high enough for the door to be accessible.

The Tidal Coast reappears in WarioWare Gold in the microgame Wario Land 3, though the level design in it is original and not from the original game.

Gray Chest: Yellow Book
The Yellow Book is inside the Gray Chest. It is available as soon as the level is unlocked.

For the Gray Key, it is all the way to the right across the water, past the Hammer-bots, the Spear-bots and the torch, where it is within the wall. In order to get the Gray Key at this point of time, Wario must use a Hammer-bot to trigger Bouncy Wario, and then bounce up the platforms to go over the wall, and then fall all the way down to the right to collect the Gray Key.

In order to access the Gray Chest, Wario must go to the torch and touch the flame to trigger Hot Wario while facing right, and then jump across the platforms until he is all the way to the right, where the Bonfire Blocks must be broken after Wario becomes completely under fire. After the blocks are broken, the Gray Chest is accessible.

After collecting both the Yellow Book from this chest and the Trident from Bank of the Wild River's Gray Chest, a lightning storm is summoned at the southern side of the world, where the ensuing lightning and rain causes a fissure, unlocking The Steep Canyon.

Red Chest: Foot of Stone
The Foot of Stone in the Red Chest. It is available after obtaining the Grab Glove from The Steep Canyon's Gray Chest, which is required to break Enemy Blocks to reach the necessary key and chest.

The Red Key is within the pipe to the right, under the Enemy Blocks. To break them, Wario must carry one of the Spear-bots to throw at them, and then access it. The area within the pipe is filled with water, where bubbles emerge from tiny openings within the water. The Red Key is blocked by currents, which Wario cannot swim past. In order to reach the area, Wario must swim under five platforms underwater, go right, and then break the blocks above. And then he must touch a bubble below to trigger Bubble Wario to float up past the current to be able to collect the Red Key.

The Red Chest is within the door all the way underwater, which Wario must go to while avoiding the bubbles. Within this door, there is a Spearhead and a series of Enemy Blocks. For the Enemy Blocks in narrow gaps, Wario must charge to throw the Spearhead to break them. After breaking the third set of Enemy Blocks, the Red Chest is accessible.

The Foot of Stone causes the earth to shake after it is thrown to the ground, causing a landslide in The Volcano's Base, a fissure to appear in The Steep Canyon, and the swamp water to drain in The Stagnant Swamp. These events reveal new entrances in those levels.

Green Chest: Electric Fan Propeller
The is in the Green Chest. It is accessible after the Statue from the Bank of the Wild River's Green Chest is collected, where it mends the grillage in order to be able to reach the chest. This treasure can only be collected at night, as the water level is high enough to enter the door where the chest is in.

For the Green Key, Wario must first go all the way right. Then he must go up and go into the room at the top, which can be accessed by either using the Hammer-bot to trigger Bouncy Wario to reach the top, or to break the wall with a Dash Attack towards the Gray Key, and then jumping up the platforms all the way up to reach the door to the left. Within this room, there are Omodon carried by Omodonmeka, which must be avoided, and then Wario must climb up the ladder. If the ground shakes due to the Omodon being thrown down, Wario will drop from the ladder. The Green Key is up the ladder and to the left.

The Green Chest is outside of the room, and in the room down below on the green block, which is positioned to be under the door, allowing it to be entered. Within this room, Wario must climb the grillage while avoiding the spikes and the Kushimushi to a door, which bring Wario to another room that contains birds and spikes. Wario must follow the path on the grillage while avoiding them to go to a door that leads him back to another door in the previous room. Here, he must climb forward on the grillage path to another door that brings him to the room with birds. After following the path laid out by the grillage, the Green Chest is reached.

The Electric Fan Propeller is used to fit the machinery in A Town of Chaos, which allows them to produce wind that are strong enough to propel Wario, though it requires the switch to turn on to run.

Blue Chest: Green Gem
The is in the Blue Chest. It requires the Sapling of Growth in A Town in Chaos' Blue Chest, which causes the Octohōn to grow big and strong so that it breaks the blocks that initially obstruct the maze.

The area with the Blue Key is behind the door near the torch. Within the cave, the water contains Octohōn that are big that if they tackle Wario, he will be pushed until he hits a wall. For the key, Wario must first break the blocks to go into the water. Within the water, he must go along the left side, and then downwards three levels, in which the Blue Key is all the way left on the fourth level down.

From the Blue Key, Wario must go up two levels along the rocky walls to the second level, and then go right to go down and to the left to the fifth level, and then go right, down, and left to the door. Within this door, Wario must go up to the surface of the water and jump to the right, while avoiding the apples thrown by the Applebies above, since Fat Wario will sink underwater before going back to normal. The Blue Chest is down the ladder and to the right.

The Green Gem does not affect the world in any way.

Enemies

 * Spear-bot (9)
 * Hammer-bot (4)
 * Flame (1)
 * Spearhead (1)
 * Omodon (2)
 * Omodonmeka (2 carrying Omodon)
 * Bird (8)
 * Kushimushi (12)
 * Octohōn (11)
 * Appleby (2)

Reaction abilities in this level

 * Bouncy Wario (via Hammer-bot)
 * Bubble Wario
 * Flat Wario (via Omodon)
 * Hot Wario (via flame)