This game has a run page on SDA!

The 1% category for Metroid Fusion is the opposite of 100%, where the difficulty comes from health and missile management. It is very difficult to finish a single segment run without saving, and thus it is recommended that a player aspiring to learn 1% first start with Any% to learn the core basics of the game, then try a segmented 1% speed run.

The low% speedrunning category is 1% because major upgrades do not count towards percentage, and there is exactly one expansion that is nearly impossible to skip (skipping it, and thus 0%, is only possible on TAS as of now). This missile tank is notoriously named BOB, and is the missile tank in sector 3 that is in a morph ball tunnel that Samus is required to roll through. Besides BOB, the player skips all other expansions, ending with 99 health, 15 missiles, and 10 power bombs.

The core route for 1% is the same as Any%, except the player skips all expansions except for the BOB missile tank. However, much of the difficulty in in 1% isn't just the boss strategies themselves, but specific room strategies that are difficult to do.

Current Fastest Time

0:49 Single-Segment by Biospark on SDA

0:48 Segmented by Biospark (unrecorded)

Leaderboards for Metroid Fusion 1% can be found here