As this is a Moment of Awesome page, spoilers will be left unmarked. You Have Been Warned!
Luigi is able to body-slam ghosts with the Poltergust G-00. He can use the ghost he's currently sucking up to deal damage to other ghosts, too, giving him an edge in the fights.
When you explore the empty guest rooms right after Luigi's friends are captured, you can see Peach's parasol bent on the ground. It looks like she didn't go out without a fight and whacked some ghosts with it until she was overpowered.
There are far clearer signs of a struggle in Mario's room, namely the toppled chair, messed up bed and loose objects in disarray. Whoever tried to pin down the Italian plumber clearly had a hard time.
Luigi is running terrified in the beginning to avoid being shoved into a portrait by King Boo. This is understandable considering that he has no way of fighting back without a Poltergust vacuum. After his escape into the laundry chute, Polterpup wakes him up and leads him to the garage, where a familiar car has a new and improved Poltergust in its trunk. Luigi's response is an excited "O-ho-ho-ho!" followed by triumphantly holding it up before eagerly donning the anti-ghost weapon and doing a little dance. While he still scares easily during the gameplay, now he has a way to fight back and clearly relishes that.
Luigi and Mario briefly teaming up to climb to the roof and save Peach, just like in the old days. They even have the same dynamic as in the Mario and Luigi series. Unfortunately, this is short-lived as it's ultimately a trap by King Boo to get everyone in the same place so he can seal everyone in a portrait at once.
The final battle. Luigi faces off against King Boo on the hotel roof, all while the enlarged portrait holding his friends and brother slowly comes down on the hotel, threatening to trap both of them inside. Luigi, against all odds, finally vacuums King Boo into his Poltergust just in time to stop the painting from engulfing the entire hotel and saves everyone.
The above action shows just how done King Boo is with everything and how he's been driven to his breaking point by Luigi of all people. His final effort at winning can be seen as driven not just by rage but also by desperation to not lose to the same godforsaken coward again.
The stare-down that Luigi and King Boo have as Luigi vacuums King Boo into the Poltergust. Luigi looks afraid at first, and even looks away for a second, only to glare back at King Boo with a renewed look of determination as King Boo is finally sucked into the Poltergust.
You gotta give points to King Boo in this game as it's clear he learned some lessons from his last defeat. At the start of the game, he captures all of Luigi's friends (including E. Gadd and the Toads) and ambushes Luigi while he doesn't have his Poltergust, only failing thanks to Luigi jumping into a nearby laundry chute. But even when Luigi meets with E. Gadd and makes this way to the hotel, he's still ready for him. He knew that Hellen would ultimately fail him, so he devises a clever plan to lure everyone into one final trap. He takes Peach's painting and places it on the roof, leaving Mario with Hellen. He knew that Mario, being Mario, would daringly rush in to save Peach on the rooftop after being saved himself and that Luigi would follow after. Meanwhile, while the Mario Bros. are scaling the final portion of the hotel, King Boo makes his way into the basement and uproots E. Gadd's lab with E. Gadd and the Toads still inside. Finally, when Peach is reunited with Mario and Luigi, King Boo ambushes the three and reveals that he has re-captured E. Gadd and the Toads. He stuffs them in a portrait, and proceeds to drop it on the rest of the gang, sans Luigi thanks to an inadvertent Diving Save from Polterpup. If it weren't for this entirely unintended assistance, King Boo would've won. This easily cements King Boo as one of the most dangerously competent villains in the Mario universe, who only lost due to dumb luck.
Right after getting rescued by Luigi, Mario is encouraged to follow him to the makeshift lab E. Gadd set up to stay safe with the other Toads. Does he follow him? Heck no! He encourages Luigi to follow him and rushes straight to the top of the tower, jumping over gaps and even wall jumping to get to the top of the tower! Only 10 seconds after getting rescued and he is up and running!
As he's leading the charge to the top of the hotel and the confrontation with King Boo, Mario makes generous usage of the various mobility techniques he's gained over his years in the 3D games, especially the sideways flip and wall jumping, which any long-time 3D Mario players know to be especially versatile.
Super Suction. Once you finally get this power-up and find a wall socket to hook it up, be amazed at the awe-inspiring power now under your control as it destroys everything in the surrounding room. Even the background music conveys a sense of awe and horror more befitting of a Card-Carrying Villain than a Lovable Coward hero, especially when used in one optional area. Unfortunately, it's such a Story-Breaker Power that you only get one mandatory use out of it to progress in the main game (and three overall), but it's very much worth it.
conveys a sense of awe and horror more befitting of a Card-Carrying Villain than a Lovable Coward hero, especially when used in one optional area. Unfortunately, it's such a Story-Breaker Power that you only get one mandatory use out of it to progress in the main game (and three overall), but it's very much worth it.