Boomsday Machine Daredevil Run is the second mission of Bowser Jr.'s Boom Bunker. It is available after Mario grabs the Comet Medal on the Spinning Platforms Planet in the same galaxy's first mission. Due to its nature as a Daredevil Comet, this mission bans healing and Mario basically has to redo the main mission without getting hurt.
The mission starts off like the first, though no coins appear. However, Mario encounters a different area in this mission after he leaves the Cannon Planet. Instead of landing on the Spinning Platforms Planet, Mario will land on the Dark Matter Area on his way to the boss. A lone Koopa Troopa appears immediately after the target, and Mario must board a swinging platform, but must move to avoid the Dark Matter's patch.
On the boss planet, Mario and Bowser Jr. square off again, just like they did in the first mission, as Bowser Jr. uses the Boomsday Machine.
- When Mario hits their bulls-eye and gets a 1-Up, the first target turns blue with white markings, and the second target, now easier to hit since it is tilted so that its front side is closer to facing the cannon, gains a grey marking.