Super Metroid: X-Fusion is a Super Metroid hack that recreates Metroid Fusion, with a large number of changes in the story, level design, and enemies while still be faithful enough to be considered a Fusion remake. Lots of bosses returning from the original game, as well as some X-infected versions of Super Metroid's bosses.
Bounty hunter Samus Aran is infected by shapeshifting X Parasites. To save her, doctors inject a vaccine derived from a baby Metroid's DNA. Sent to investigate a quarantined research station, Samus must battle the multiplying parasites and a deadly, unstoppable clone of herself known as SA-X.