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The 100% category for Metroid Fusion is the opposite of 1%. Instead of worrying about health and missile management, the player must remember item placements and room strategies, and most of all, 100% cleanup, which is the most difficult segment of the entire category. Samus will end with 20 e-tanks, 250 missiles, and 74 power bombs.

Many new players have the misconception that 100% is easier than any% because the player is forced to have more energy and missile tanks for bosses. However, strategies for both categories are exactly the same; if the player is relying on an overload of expansions to pull them through the bosses, then it is clear that the player does not know how to fight bosses.

It is highly recommended that the player start with learning Any% first, as most strategies and skills learned in Any% will easily carry over to 100%.

Current Fastest Time

Unrecorded: 1:06 by Biospark

Recorded: 1:07 by kirbymastah

Leaderboards for Metroid Fusion 100% can be found here

Route

Each section of the game will have a counter of how many energy tanks, missile tanks, and power bomb tanks the player should have by the end of it. It is also recommended to be playing on a New Game+ file, as the game provides a checklist of how many of each type of expansion Samus got in each sector, or in the entire game.

Abbreviations: ET = Energy Tank, MT = Missile Tank, PB = Power Bomb Tank

Main Deck Beginning

The route is the same as Any%, past obtaining the main Missile upgrade. Collect MT1 and MT2 the same way as in Any%, in the dark vertical shaft.

Collect both ET1 and ET2 before Arachnus. ET2 can be found by missiling the leftmost block of the right part of the ceiling before falling into the fight.

Because you have used one missile for ET2, Arachnus is more difficult than in Any%. It is important to make sure you have enough missiles for the core-x.

Collect MT3 after the navigation room with morph ball, just as in Any%.

Count: 299 Health, 25 Missiles

Sector 1 - Charge Beam

There are many obtainable missile tanks in Sector 1; however, it is faster to collect all of them during cleanup.

The route here is the same as Any% except to also collect ET3 in the toad room after the first stabilizer.

Count: 399 Health, 25 Missiles

Sector 2 - Bombs & Hi Jump

The route up until collection of Bombs is the same as Any%.

After leaving the Bomb Data Room, get MT4 in the top right corner by bombing the blocks.

In the next room, do a walljump to reach the hidden morph ball tunnel in the top-left corner. Bomb the floor to reveal a pillar to reach MT5.

Two rooms ahead, fall into the bottom-left pit with the blue zoro. Collect MT6 here by bombing the bottom-right corner of the pit. Be careful not to take more than one hit from the blue zoro, as it does enough damage to kill you.

Follow the Any% route, but get ET4 in the room just before Zazabi.

After Hi-Jump, you can skip the SA-X encounter by intentionally being frozen and hit by a super missile (this does a total of 300 damage), abusing the mercy invincibility to run through SA-X and either escape safely or spin jump over the ice beam shot it fires at you. If you are frozen a second time, you have a very small time window to jump before the super missile hits you, assuming you ran far left; however, you'll be left with 1 HP. This skip not recommended for newer runners though, and is somewhat luck-dependent.

Leaving Sector 2 after Hi-Jump follows the same strategy as Any% besides the SA-X skip.

Count: 499 Health, 40 Missiles

Sector 4 - Speed Booster

Follow the Any% route until the path splits with two doors on the left side. Instead of taking the bottom door, take the top door and follow the long path to collect ET5.

Return to the fork, take the bottom door, and after crossing the water, go to the room above and climb into the hidden morph ball tunnel on the left to collect MT7.

Follow the Any% route until after obtaining Speed Booster. After breaking the speed boost blocks immediately after Serris, instead of falling all the way down, reveal the morph ball tunnel on the left wall to find both MT8 and MT9.

After lowering the water level, get MT10 immediately below the switch. After speedboosting through the hidden path on the bottom of sector 4, shinespark through the pond above with MT11 in plain sight.

Leave Sector 4 as normal.

Count: 599 Health, 65 Missiles

Sector 3 - Super Missiles

Sector 6 - Varia Suit

Sector 5 - Ice Missiles

Meltdown

Save the Animals

Sector 5 - Power Bombs

Main Deck - Space Jump

Sector 2 - Plasma Beam

Nettori is one of two bosses where the 100% strategy differs significantly from Any%. Because you have so many missiles, it is best to simply use missiles for the entire fight, as firing only missiles is the best human form of DPS at this point in the game.

Laying power bombs in between missiles is theoretically faster, but for a power bomb to save time, it must be planted before the cooldown of the previous missile is complete. In other words, it will waste time for real speedruns (But used in TAS).

Sector 5 - Gravity Suit

Sector 4 - Diffusion Missiles

Sector 6 - Wave Beam

Sector 1 Cleanup

Sector 3 Cleanup

Sector 5 Cleanup

Sector 6 Cleanup

Sector 2 Cleanup

Endgame