Here is the main storyline of Pikmin, Olimar's journey to save himself.
 The Impact Site
One day, during an interstellar vacation, Olimar's ship is impacted by a rogue asteroid and is sent tumbling down onto a mysterious planet, with parts of his rocket, the Dolphin, breaking off and scattering across the land. When he awakes to find his ship in ruins, he decides that he must try to gather the parts and repair his beloved Dolphin in an attempt to return home. He then realizes that the atmosphere of the planet he has landed on contains an abundance of oxygen, which is poisonous to Hocotatians. His life support system can only keep him alive for 30 days. After exploring the area for a little while, he discovers an odd type of ship that resembles an Onion. When he disturbs it, a lone Red Pikmin Seed flies out. Once it sprouts, Olimar plucks it from the ground and notes its striking similarity to a Pikpik Carrot, one of Olimar's favorite treats back on his home planet of Hocotate. He notices that it follows him and takes instructions. With his new partner, he collects the Pellets from Pellet Posies and makes more Pikmin. After producing enough Pikmin to push away a Cardboard Box, he discovers the Main Engine to the Dolphin (what a find!). Olimar decides to rest for the remainder of the day. he calls the Pikmin back into their onion, and, after installing the engine, flies his ship into the lower atmosphere of the Pikmin Planet to avoid the nocturnal monsters. But to his surprise, the red onion that he found also takes flight and follows hims. He writes about his travels and discoveries in his Journal. The next day, he decides to leave The Impact Site and investigate a new part of the planet, which he calls The Forest of Hope.
 The Forest of Hope
For the first time, enemies are encountered. Red Bulborbs and Dwarf Red Bulborbs patrol the entire area. He is able to overcome their might though with the help of the Pikmin. He discovers that having the Pikmin bring the corpses of defeated enemies back to the onion creates more Pikmin too! Later, he finds a yellow onion, along with the Yellow Pikmin. They help him acquire the Whimscial Radar, which allows Olimar to locate other parts easily. After recovering a few more parts, the Dolphin is able to fly just a bit farther. He decides to travel to a large trench in the middle of the surrounding forest. He calls it The Forest Navel.
This Area seems to be partially underground due to high amounts of volcanic activity and low light levels. It's also got loads of new and difficult enemies and hazards, like Fiery Blowhogs and Fire Geysers. In this area, Olimar discovers yet another onion, this time with Blue Pikmin, which he uses to collect treasures in the water. After defeating the fearsome Beady Long Legs and the poisonous Puffstool, and collecting more ship parts, he is able to move on to a swampy-looking area a bit north of the forest. He decides to name it The Distant Spring.
 The Distant Spring
Olimar lands here and discovers it has a lot more parts than the other locations. The enemies here are also a lot tougher and more plentiful. Not only that, but there are many stone ruins found in this area that take skill and strategy to pass through. The blue Pikmin come in handy here, because much of the level is made up of a shallow sea. Enemies such as the Puffy Blowhog and Spotty Bulbear reside here. Once Olimar completes the overwhelming task of recovering 29 parts, he is able to travel to the 5th and final area, where the last ship part is hidden.
 The Final Trial
When Olimar first arrives at The Final Trial, he is surprised to find that there are no enemies. However, he does have to utilize the abilities of all the Pikmin to build bridges, moves boxes, break down walls and make it to the other side of the level. He stumbles upon a large circular "arena", with an odd-looking plant in the middle. When he approaches to get a closer look though, the "plant" springs to life and emerges from the ground with a loud and intimidating roar. This creature is none other than the game's final boss, the Emperor Bulblax. Olimar must use his Pikmin strategically to defeat him. The battle rages on for what seems like forever until Olimar is able to overcome the beast and reveal the final ship part, the Secret Safe.
Depending on what ship parts you collect, there are 3 possible endings.
 Bad Ending
You get this ending if you do not collect the 25 required ship parts within the 30 days. Olimar attempts to leave the planet, but he crashes back down and dies. The pikmin find his corpse and take him to the onion. When he is sucked in though, the onion releases an odd looking seed... one with Olimar's face! The Pikmin then dance around him as the scene fades out. Because Olimar has to make it back to Hocotate for the events in Pikmin 2 to take place, this is not the true ending to Pikmin.
 Good Ending
You get this if you recover the 25 required parts, but not all 5 optional ones. Olimar blasts off and succeeds, but is sad to leave the Pikmin and is worried about their well-being.
 Happy Ending
This is complete ending to Pikmin. You must recover all 30 ship parts to get this ending. As Olimar leaves the planet on his fully-restored Dolphin, the Pikmin are seen waving to him and attacking a Red Bulborb all by themselves. Olimar is happy for the Pikmin. As he blasts off, he sees their onions fly up into the atmosphere with him one last time, along with many other onions, all of different colors not seen in the game. Olimar then flies away through space happily.
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