Bowser Jr.'s Boomsday Machine

Bowser Jr.'s Boomsday Machine is the first mission of Bowser Jr.'s Boom Bunker in Super Mario Galaxy 2. The objective is to defeat Bowser Jr.'s Boomsday Machine.

Mission
The player starts on a planet with a destroyed Megahammer, which the Toad Brigade Captain claims is no longer working. Getting near him will cause a Bullet Bill to fire, and the player has to lead it to a cage opposite from where the player starts to reveal a cannon. Using the cannon, the player has to fire at either a pole or a target to land on the planet with Boomerang Bros. Defeating the Boomerang Bros. will cause a Launch Star to appear, which will send the player to the planet above. Using the cannon there, the player has to avoid the Space Mines and land on a platform on the planet ahead. Here, the player has to use a Cloud Flower to cross to the platform in the center, and Ground Pounding the stone slabs in the center will cause a Launch Star to appear, which will launch the player to the planet where Bowser Jr.'s Boomsday Machine is fought.

The Boomsday Machine is a large tower with Fire Bars rotating around it and its cannons will fire balls of electricity that will destroy any created clouds. To damage the machine, the player has to create a cloud over a wind turbine to gain height, then use more clouds or a Long Jump to reach the top of the tower and Ground Pound the cockpit Bowser Jr. is in. The Boomsday Machine will then begin sucking in any clouds in the area, so the player has to wait for them to stop before creating any more. The tower will also be covered in electricity at this point, preventing the player from damaging the cockpit. After damaging the cockpit a second time, more of the tower will rise out of the ground, revealing wheels. The tower will then begin moving around the arena as it tries to attack the player. The extra height also means the player has to create more clouds to reach the top of the tower. After damaging the cockpit once more, the tower will explode and the player will earn the Grand Star.