15-Minute Melee and Brawl

15-Minute Melee and 15-Minute Brawl are Multi-Man modes in Super Smash Bros. Melee and Brawl, respectively. They challenge the player to defeat as many opponents as possible (Fighting Wire Frames in Melee, and Fighting Alloys in Brawl) within 15 minutes without falling from the stage or self-destructing. These are arguably two of the more difficult Multi-Man Melees and Brawls, though simple strategies such as spamming a certain move or evading the opponents altogether will suffice.

The high scores of 15-Minute Melee and Brawl depend on whether or not the match is cleared. If it is cleared, a record is made of the amount of opponents knocked out. If it is not cleared, a record is made of the length of time which the character lasted.

Strategies
Most of the simpler strategies for the 15-Minute Melee and 15-Minute Brawl involve spamming a certain move of the character. It is also recommended to ignore any kind of item, especially those which are explosive.

Donkey Kong
Playing as Donkey Kong, situate him anywhere on the stage. When the Fighting Wire Frames begin approaching Donkey Kong, use his Down Special Move, the Hand Slap. Any Fighting Wire Frames in the radius of this move should be knocked out instantly.

Dr. Mario
Playing as Dr. Mario, spam his Down Special Move, the Dr. Tornado, back and forth along the stage.

Falco
Playing as Falco, spam his Side Special Move, the Falco Phantasm, back and forth along the stage.

An alternative method while using Falco is to sit on the far right side of the stage and continually spam his blaster. On occasion a wireframe may obtain a starman. While the starman is in effect, spam his Side Special Move, the Falco Phantasm, back and forth until the starman wears off. Then continue to sit on the right side and spam his blaster. This will not work with Fox due to the fact that Fox's blaster does not flinch the enemy. It is possible to complete the challenge and not get hit using this method.

Fox
Playing as Fox, spam his Side Special Move, the Fox Illusion, back and forth along the stage.

Kirby
Playing as Kirby, situate him on the edge of a main platform, facing inwards, and use his Up Special Move, the Final Cutter. If necessary, roll to the other side of the platform to avoid a Bob-omb or similar hazard.

Luigi
Playing as Luigi, spam his Down Special Move, the Luigi Cyclone, back and forth along the stage.

Mario
Playing as Mario, spam his Down Special Move, the Mario Tornado, back and forth along the stage.

Mewtwo
Playing as Mewtwo, situate it on the edge of a main platform and use its Standard Special Move, the Shadow Ball. Any Fighting Wire Frames in the radius of this move will be damaged. If Mewtwo is damaged, launch the fully-charged Shadow Ball, and return to the edge of the main platform to start over.

Screw Attack
Hold off the wire frames until you get a screw attack ball. While this would be useless against real fighters the wireframes will be KO'd on contact. If you can hold on to the item the whole time, you can easily get through 15 minutes mostly untouched.

Ice Climbers Do the Ice Climber Freeze Glitch to freeze all the wireframes,then simply wait around until the time is up.(It helps to literally freeze them to prevent accidental release).Be careful though. Sometimes, while attacking the helpless wire frames, a bob-omb will suddenly appear and kill you.

Lucario
This strategy requires two players. Both players must be Lucario. Both players must stand beside each other using Lucario's standard special attack. When a Fighting Alloy jumps up to the players, they will be caught between the two attacks and will not be able to move. 

Pikachu
Stand in the center of one of the side platforms (left works better) and spam Pikachu's Thunder ability.

Jigglypuff
Fly around the stage and use Pound. Its good jumping ability is also useful for stalling by not attacking the Alloys or remaining inside their attack range. You could also alternate between grabbing ledges. Hang on to one edge, jump off, and float underneath to the other ledge and grab on to that. Keep repeating this step until the 15 minutes are up.

Luigi
Spam the Luigi Cyclone back and forth across the stage. Using the Cyclone in the air should instantly kill any Alloys it touches, whereas using it on the ground will only knock them out on the final hit. Aerials, especially nair and bair, are also useful here.

Ike
Stand beneath the center of one of the side platforms (left works better) and spam Eruption repeatedly. All power levels should work at KO'ing the Alloys

Yoshi
Keep fighting until there is only one alloy left, and the alloys stop appearing. (There's a certain time when new alloys will only appear when you've defeated all of the alloys you have currently.) Then stand to the platform on the left (or right) and stay there. If the alloy comes to attack, simply double jump to get to the platform on the opposite. (This is when Yoshi's high double jump comes in handy) DO NOT attack the alloy, as doing that may result in KOing it and new ones appearing again. If explosive items appear (e.g. Smart Bombs, Blast Boxes etc.), throw them away. Don't let the alloy accidentally detonate it. This may not be as easy as the other ones listed here, but it's very effective.

King Dedede
Stand on the very edge of the lowest level, and transition into your continuous AAA Hammer spin by holding down A indefinitely. The advancing Alloys will simply bounce away when in contact with the Hammer, even KO at large percentages. This won't get many kills, but since you've got 15 minutes, it does help to clear this for the first time. Beware, as Alloys will attack from a distance, hitting the Hammer and interrupting the Hammer Spin. If they come to close, just Down Smash, Hammer Sweep, them away. Never use the Forward Smash, but you can use the Up Smash if you fear an Alloy descending through the platform above you and attacking; the Hammer reaches above the platform

In Super Smash Bros. Melee
Clearing 15-Minute Melee will result in unlocking the Kongo Jungle stage, which originally appeared in Super Smash Bros..

In Super Smash Bros. Brawl
Clearing 15-Minute Brawl give you the Green Alloy trophy.