Brilliant title. It oozes atmosphere, Horror and adventure.
Metroid Fusion uses its linear approach to full effect and creates a challenging and riveting experience that always stays true to Metroid. It is incredible fun and wonderous that they could create such an intense game for the Gameboy.
The story is the best in the series and SA-X besting you is just captivating. The level design and hunt for items is well-built like always, too.
I have but two little nitpicks: the gauntlet from Yakuza to Nettori is extremely limiting and If you have struggled before, you're gonna have a bad time. Furthermore it is not nice that you are not allowed to save after the boss fight against SA-X.

Definitely play this!