Interesting... I always wondered why Nintendo never went ahead and gave Return of Samus the Zero Mission treatment. I played through the GB game for the first time earlier this year (I played the game before on my cousin's GB waaaay back in the day, but never got too far), and it's interesting but with flaws. The monochrome environments are real repetitive (and without a map it's really tough to navigate), and some of the more complex maneuvers (ie the space jump) have clunky controls. The best part of the game is the music, really creepy ambient sounds and noise music it's very unsettling especially the further you get into SR-388.