Mewtwo will appear at random at the end of a multi-player match and challenge the winner. He will be unlocked as a selectable character after he is defeated. Alternately, in versus mode, play 700 battles or get a total of 20 hours of game play.
To unlock Mewtwo, play 20 hours in melee vs. mode (combined number of human players times the number of hours). For example, if you play 1 human player vs. 3 CPU players, play 20 hours; 2 players vs. 2 CPU players, play 10 hours; 3 players vs. 1 CPU player, 7 hours; 4 player vs., 5 hours.
To get Mewtwo easily, go into Custom Rules Melee and change "Stock" to "3" and "Item Flow" to "None", and "Stock Time Limit" to "Off". Choose two of your best characters (for fighting Mewtwo) and go into a match in the Pokemon Stadium level. Place both fighters on the Pokeball in the middle. Do not pause the game. Unplug the controllers, and leave the system on overnight to accumulate game time. Plug in the controllers again, and have one of the fighters die three times. If enough hours have been obtained, Mewtwo will challenge you. Defeat him to unlock him next to Jigglypuff as a playable character.
This trick is useful if you do not have a second controller and want to unlock Mewtwo. Enter the "Custom Settings" screen, and set up a versus game with a "Damage Ratio" of "0.5" and a "Stock" of "99". Start a Tiny Melee with a human as player one (preferably being a character you can defeat Mewtwo with) and three other players at a low CPU level of 1. Start the game at Hyrule Temple, then leave it idle overnight. For best results, have the three CPU players be Captain Falcon, Prince Marth, and Pikachu. About eight and a half hours later, the fight should just have ended. Repeat the process every night until you have accumulated twenty hours and can fight Mewtwo. However, the human player should be the winner of the final fight or Mewtwo may not appear. Note: You can see how many versus hours you have accumulated by going to the "Misc VS Data" section.
Set up a one life battle with as many humans as possible and no CPU players. Leave the game on overnight, then defeat the other players and Mewtwo.
Mr. Game & Watch:
Complete the game in classic mode with all characters.
Alternately, complete the target test mode with all of the other 24 characters.
Alternately, play over 1,000 versus mode matches.
Pichu:
Accomplish one of the following:
Unlock both Luigi and Falco to unlock event mode #37 (Legendary
Pokemon). Complete event mode #37. After winning, Pichu will become
playable.
Complete adventure mode as Mewtwo.
Play 200 matches in versus mode.
Prince Marth:
Play with all 14 default characters in classic mode without continuing. Alternately, play vs. mode more than 400 times.
Alternately, play versus mode with all of the default characters. Marth will challenge the last character you played as (if you won the match). If you lose against him, then he will reappear to challenge the winner of the next versus match.
Roy:
Successfully complete the game as Prince Marth in classic mode.
Alternately, play over 900 versus mode matches.
Young Link:
Finish classic mode 10 times with different characters each time. One time must be with Link.
Alternately, complete adventure mode as Ganondorf.
Alternately, play 500 versus mode matches.
Alternately, complete classic mode with Ness.
Battlefield stage:
Successfully complete the game in all-star mode.
Big Blue stage:
Play 50 multi-player matches. Either the Brinstar Depths, Fourside, Poke Floats, and Big Blue will be randomly unlocked every 50 matches. Play another 50 matches to unlock the next stage until all are unlocked.
Alternately, play 150 multi-player matches.
Brinstar Depths stage:
Play 50 multi-player matches. Either the Brinstar Depths, Fourside, Poke Floats, and Big Blue will be randomly unlocked every 50 matches. Play another 50 matches to unlock the next stage until all are unlocked.
Alternately, play 50 multi-player matches.
Dream Land stage:
Successfully complete the game in Break The Targets mode with all fighters.
Final Destination stage:
Successfully complete event mode #51 (The Showdown).
Flatzone stage:
Successfully complete the game as Mr. Game & Watch in classic or all-star mode without losing a life.
Fourside stage:
Play 50 multi-player matches. Either the Brinstar Depths, Fourside, Poke Floats, and Big Blue will be randomly unlocked every 50 matches. Play another 50 matches to unlock the next stage until all are unlocked.
Alternately, play 100 multi-player matches.
Kongo Jungle stage:
Successfully complete the 15 Minute Melee.
Mushroom Kingdom II stage:
Win a Birdo trophy to unlock the Mushroom Kingdom II stage from Super Mario Brothers 2. Try putting a lot of coins in the lottery to get it.
Alternately, successfully complete adventure mode with five characters.
Poke Floats stage:
Play 50 multi-player matches. Either the Brinstar Depths, Fourside, Poke Floats, and Big Blue will be randomly unlocked every 50 matches. Play another 50 matches to unlock the next stage until all are unlocked.
Alternately, play 200 multi-player matches.
Yoshi's Island stage:
Hit over 1300 feet in homerun derby mode with any character.
Random stage select:
To unlock the "Random Stage Select" option in Additional Melee Rules, first unlock all of the stages except Battlefield, Final Destination, and the three Past Stages. This allows you to decide which stages will be included and which will be omitted when you randomly select a stage.
Alternately, complete classic mode with all characters.
Extra Events (#31-#39):
Complete the first 30 events and unlock Jigglypuff, Luigi, Dr. Mario, Falco, and Young Link
Extra Events (#40-#50):
Unlock all the characters in the game.
Event #51:
Clear all other events.
Alternate music:
Hold L or R and select a stage in multi-player mode. Keep the button held until the match begins. Note: Only certain stages have new music.
Hold A and press Start at the title screen. Different music will play at the main menu.
Use the following trick to listen to any desired music in the gallery of trophies. After unlocking the Sound Test, use it to find a song you like, then press A to play it. Then, press B to exit. When you go to the trophy gallery, that song will be playing instead of the usual one.
Sound test:
Unlock all stages, all characters and all 51 events.
All-Star mode:
Unlock all bonus fighters to unlock the single player All-Star mode. This mode allows you to fight all game characters, but with less health items.
All-Star mode stages:
Every character in All-Star mode has a specific stage you fight them in, even if it is not their stage. Eventually, you will fight two opponents at a time, and then three opponents at a time. Use the following trick to find out what stage you are going fight in. On the little path with the three hearts and the teleporter to the next fight, there are small TV screens that appear behind the teleporter. These screens show you what opponent(s) you are fighting next. When it shows two opponents, you will be in the stage of the one on the left. When it shows three opponents, you will be in the stage of the opponent in the middle.
Mario: Rainbow Cruise
Peach: Princess Peach's Castle
Donkey Kong: Kongo Jungle
Yoshi: Yoshi's Story
Link: Great Bay
Zelda: Temple
Captain Falcon: Mute City
Bowser: Yoshi's Island
Fox: Corneria
Samus: Brinstar
Pikachu: Pokemon Stadium
Ice Climbers: Icicle Mountain
Kirby: Green Greens
Ness: Onett
Dr. Mario: Mushroom Kingdom II (Subcon)
Falco: Venom
Pichu: Fourside City
Luigi: Mushroom Kingdom
Jigglypuff: Poke Floats
Mewtwo: Battlefield
Mr. Game & Watch: Flat Zone
Marth: Fountain of Dreams
Roy: Final Destination
Young Link: Jungle Japes
Ganondorf: Brinstar Depths
Score display:
To unlock the "Score Display" option in Additional Melee Rules, accumulate more than 5,000 KOs in melee matches. This enables you to show or hide the score during melee matches.
Trophy arrangements:
Hold L and enter the Collection to arrange your trophies in rows. Hold R and enter the Collection to arrange trophies in a circle. Hold Y and enter the Collection to arrange the trophies in a triangle.
Hint: Trophies:
The trophies you win in adventure mode are different then the ones won in classic mode. The ones in classic mode give you tips about the character(s) who have won adventure mode.
In the Underground Maze level in adventure mode, do a throw move on almost anything (such as Likes, Octoroks, and ReDeads). There is a good chance a trophy will appear.
Hint: Battlefield trophy:
Successfully complete all-star single player mode.
Hint: Bunny Hood trophy:
Perform over 125 combos with all characters combined in training mode.
Hint: Captain Olimar trophy:
Insert a memory card with a saved game from Pikmin. Begin the game and a Captain Olimar trophy will be available.
Hint: Celebi trophy:
Get Celebi in a Pokeball.
Hint: Crazy Hand trophy:
Successfully complete adventure mode under the hard or very hard difficulty setting without using any continues.
Hint: Diskun trophy:
Get all end-of-level bonuses and penalties.
Hint: Donkey Kong Junior trophy:
Play in any single player mode with all twenty-five characters.
Hint: Entei trophy:
Successfully complete event mode #26 (Trophy Tussle 2).
Hint: F-Zero Racers trophy:
Successfully complete adventure mode with all twenty-five characters.
Hint: Falcon Flyer trophy:
Fight 150 versus mode matches.
Hint: Female Wire Frame trophy:
Get over 100 KOs in Endless Melee.
Hint: Fighting Wire Frames trophy:
Successfully complete 15-Minute Melee.
Hint: Final Destination trophy:
Successfully complete all events, including event mode #51.
Hint: Food trophy:
Fight 1,000 versus mode matches.
Hint: Game & Watch trophy:
Successfully complete event mode #45.
Hint: Giga Bowser trophy:
Successfully complete adventure mode with any character under the normal or higher difficulty setting. You will have to fight Giga Bowser after you defeat the normal Bowser. You cannot use any continues.
Hint: Goomba trophy:
Successfully complete event mode #14 (Trophy Tussle 1).
Hint: Heart Container trophy:
Fight 100 battles in versus mode.
Hint: Kirby Hat 4 trophy:
Unlock Mr. Game & Watch. Alternately, fight 100 coin battle matches).
Hint: Kirby Hat 5 trophy:
Complete event mode #37 (Legendary Pokemon). Alternately, unlock all eleven secret characters.
Hint: Kraid trophy:
Fight 50 battles in versus mode.
Hint: Landmaster Tank trophy:
Have more than 1000 KOs total for all characters.
Hint: Lip's Stick trophy:
Perform a 20+ combo in training mode.
Hint: Lon Lon Milk trophy:
Successfully complete Target Test with all characters in less than twenty-five minutes.
Hint: Mach Rider trophy:
Complete single player adventure mode in less than five minutes.
Hint: Majora's Mask trophy:
Successfully complete event mode #47 (Trophy Tussle 3).
Hint: Male Wire Frame trophy:
Successfully complete 100 Man Melee under 240 seconds.
Hint: Marin trophy:
Unlock the sound test option.
Hint: Master Hand trophy:
Successfully complete classic mode with any character under the hard difficulty setting. You can have any amount of lives, but do not use any continues.
Hint: Maxim Tomato trophy:
Fight ten battles in versus mode.
Hint: Meowth trophy:
Successfully complete all-star mode with all twenty-five characters.
Hint: Metal Box trophy:
Perform a 10+ combo in training mode.
Hint: Mew trophy:
Complete all-star mode under the hard or higher difficulty setting.
Hint: Motion-Sensor Bomb trophy:
Successfully complete event mode #3 (Bomb-Fest).
Hint: Mr. Resetti trophy:
Kill more than five opponents in cruel melee mode.
Hint: Mute City trophy:
Get over 10,000 meters as the total distance walked by characters.
Hint: Paper Mario trophy:
Hit over 1476 feet (one mile) in homerun derby mode.
Hint: Sandbag trophy:
Hit over 984 feet in homerun derby mode.
Hint: Sheriff trophy:
Successfully complete Target Test with all characters with a time less than 750 seconds.
Hint: Smash Coins trophy:
Fight 100 coin battle matches.
Hint: Sudowoodo trophy:
Fight 200 battles in versus mode.
Hint: Target trophy:
Successfully complete Target Test with all characters, including the bonus fighters.
Hint: Tom Nook trophy:
Collect over 1,000 coins. Note: Spent coins do not subtract from the number needed.
Hint: UFO trophy:
Fight 100 battles in versus mode.
Hint: Unown trophy:
Set a combined homerun contest record of 16,404 feet.
Hint: Wario trophy:
Successfully complete All-Star single player mode without using any continues.
Hint: Wolfen trophy:
Successfully complete adventure mode in less than 18 minutes.
Hint: Trophy list:
There are a total of 290 trophies in the game.