This is honestly one of the greatest fan games I have ever played. The only exception in terms of fan games is the Sonic community, but the fact that Metroid II got a stellar Zero Mission-style remake done by a small group of fans is just awe-inspiring. Only issues I personally have with it is that it never got any official updates past 1.1, though fans have, and still are, rectifying that, and the Metroid fights are kind of bad and luck dependent. Otherwise, great game.