If none of your Pikmin die in the Pikmin games and you beat it nothing happens other than beating the game.
It is best to try to enter as many caves as possible, as quickly as possible. This is where most of the treasure in the game is, and this will help you to pay off your debt. The shortest time it has ever taken someone to get every treasure in Pikmin 2 is eight in-game days.
In Pikmin 2, you just get "The Key". In Pikmin 1 and I believe Pikmin 3, you have to beat the game.
You can't. Besides there not being enough time in the in-game day, the necessary ship parts are scattered across five areas, and one can only visit one area per day. The fastest possible time to beat Pikmin in is about 9 in-game days. The longest amount of time is 30 days. If you surpass the 30 day time limit (in-game time, not real life time), you will view a different ending depending on how much treasure you have collected.
Up to 100 Pikmin can be outside at a time. This includes wild Pikmin of colors you haven't discovered yet.
My friend beat it in under a week.
If you mean the Emperor Bulblax, he can be a toughie. I once saw a guy on YouTube beat him with not a single Pikmin death! In fact, he beat the whole game in 9 days with out 1 Pikmin dying! Anyway, use mostly Red Pikmin, the more with flowers the better. Also use Bomb-rocks. I lost 198 Pikmin on this fight, hopefully you can do better!
Unlike the first Pikmin, Pikmin 2 does not involve a time limit. Thus, the game has a more relaxed pace than its predecessor.
To beat Pikmin 2, you need to pay off Hocotate Freight's 10,000 Poko debt. To complete the game (which could also be called beating it), you need to gather all the treasure.
White Pikmin are the fifth type of Pikmin introduced, first found in Pikmin 2. They are the second smallest type of Pikmin, and by far the fastest of them. They are poisonous, which gives them immunity to poison hazards and causes damage to enemies that eat them. They have no Onion, and reproduce solely through Ivory Candypop Buds, found in some underground caves. They appear in Pikmin 3 only in Mission Mode and Bingo Battle.