Save yourself the headache and just play AM2R.
Nintendo should have just remade Metroid II instead of giving us Metroid: Federation Force.
Fusion is probably my favorite game in the series, only GBA game that ever made me scared! It did a better job than horror games. I really want to see a sequel to know how the story progresses.
"The strong do what they can and the weak suffer what they must" - Thoukydides