Console: Gameboy Advance
As impressive as Metroid: Zero Mission was, it wouldn’t have existed if not for the success of Fusion. And even though it came before, Fusion was arguably even more impressive than Zero Mission. Chronologically the last game in the series, it gave Metroid a little more personality than were used to, adding a secondary character – Samus’s computer, Adam – and a more coherent story that sees Samus set loose in a space-research station filled with evolving, creature-mimicking X-parasites.
Samus herself got a new look for the adventure, although there was more to it than just adding blue glop to her costume. An X-parasite infection early on in the story forces doctors to fuse her DNA with the baby Metroids. This grants her the ability to absorb parasites after destroying their host bodies, which in turn is key to earning new abilities. It was a more conventional turn for the series, but it was fun, and it helped make Fusion one of the greatest revivals of a classic series the GBA ever saw.