A small army of alien creatures attack a giant R.O.B., seemingly doing no damage to it. The R.O.B. knocks them off itself in a single spin, killing off most of the bizarre creatures. Their commander is Captain Olimar, who is experienced in controlling these alien beings called Pikmin. However, with most of them wiped out, he is left mostly defenseless against the impending threat. Suddenly, the Blue Falcon shoots down along the path. Out hops its pilot, accomplished F-Zero racer and bounty hunter Captain Falcon, who fells the massive R.O.B. with a powerful Falcon Punch. As he lands, he accidentally wipes out most of the remainder of Olimar's Pikmin. The two captains team up to investigate this floating island, hopefully to put a stop to the Subspace menace.
The ruined path
Go forward and defeat the R.O.B. Sentries until you reach what appears to be a bridge. Fall through it down to the area below to find a secret door. Once you enter it, you will fall right next to a trophy, and you must collect it before it falls down the small gap in the middle of the room. If you fail to do so, you can always exit and reenter the room to try again. After you collect the trophy, jump back up and continue down the path, jumping over a gap and defeating a Gamyga blocking your way forward. At the end, climb up the ladder, which will trigger a forced battle once you reach the top. There will be quite a few Auroras during the fight, which you can throw at enemies to chip their health down faster.
After the fight, keep going right until you reach some breakable brick blocks. Avoid breaking them, and use them as a staircase to reach a floating door. Inside, there are two gold item boxes. One is floating on top of some sinking blocks, so you must quickly collect it before it falls into the pit below. The other is much easier to collect, being on solid ground at the right end of the room. Jump back to the door and exit it to return outside. Go right, defeating another Gamyga blocking you, then enter the door to advance the story.
Both captains observe as the Subspace aircraft transporting the Donkey Kong trophy approaches the floating island they're standing on. Suddenly, Falco's Arwing zips by, carrying Diddy Kong as a passenger. Diddy hops out and uses his Rocketbarrel Pack to slow his descent, as he knocks away the Primid guards with his Peanut Popgun. As soon as he lands, he quickly revives Donkey Kong, who breaks free of his shackles easily. Seeing some potential allies, Captain Falcon jumps toward the aircraft, carrying a reluctant Olimar. As the four meet each other, they're attacked by more Primids. Thus, all four brawlers team up to fight off them off.
You now have to fight off several hordes of Subspace enemies. Starting off, you have to take out an assortment of Primids. Then you must avoid getting carried away by Trowlons, followed by some bomb tossing Bombeds. After that is some Shaydas, followed by a Primid and Trowlon combination, Spaaks and finally Metal Primids. Be careful not to get overwhelmed by enemies. One enemy you should especially watch out for is the Scope Primid, who usually stays far away from the fight to launch shots at you. Don't get distracted by the enemies immediately next to you and keep track of which enemy is going to attack. If you can survive until the attack ends, the stage is won.
Having defeated all of the enemies, Donkey Kong and Diddy Kong celebrate their victory. Falco congratulates them briefly before flying off into the distance. The aircraft automatically travels into a docking bay at the side of the island. The battle is not over yet...
Captain Falcon, Olimar and Donkey Kong joins your team!