Bowser's Tower appears in Mario Party: Island Tour and is served as the game's Solo Mode. It consists of thirty floors with a boss battle on every fifth floor.
The story begins with Mario and his friends having fun on the Party Islands. Bowser sees this, and, angry he wasn't invited, creates a tall tower in his likeness, with a bubble machine that traps the fun from the islands. The player character, with the help of Green Toad, proceeds to stop Bowser.
Each floor, there are three Bubble Clone copies of a random character (different from the real characters in that they shine silver and have no voice clips), and the player must compete in one of two minigames to clear the floor. If the player wins, they can move on to the next floor. Every-so-often (or after losing on the same floor at least three times in a row), a Mini Star Roulette Block will appear. Green Toad will hit the block, and the number of Mini Stars shown represents the number of character copies that will disappear, reducing the number of opponents for the next minigame. Getting a three skips the floor altogether. There are also several punishments that Bowser may choose to inflict via roulette on the player just before the 3rd, 7th, 17th and 27th floors. These "punishments" are actually nothing more than jokes or minor nuisances. After defeating the final boss, the player and Green Toad go to the top of the tower, where the player, after getting past a group of Mario copies, destroys the Bubble Machine, restoring the Party Islands to their original state. Completing the mode unlocks Bowser Jr. as a playable character.
This is the only Solo Mode in the Mario Party series that does not have an actual ending. When the character reaches the top of the tower, Bowser will reveal that the destroyed Bowser was a decoy (or that he pretended to be beaten when the player has chosen Bowser Jr.) and proceeds to knock the character and Green Toad off the tower far away, saying they can come back anytime.