Hollow and empty are words that are thrown around and indeed, the piece is sparse on instrumentation; the piano dominates, with synth elements, voice and a bit of subtle drum on it. The ambiance and beauty with the lush sounds are ponderous and the original song shines quite well. Maridia is a popular-ish song to remix for a reason, with its unnerving beauty. This reminds me oddly of House In a Heartbeat.
The good is all the instruments sound great and the filter over the quieter parts brings a nice balance so that they don't flag against the more instrument heavy parts. The flow and feel of the piece is self-contained-it's not quite a rondo (a song to be repeated several times) like all video game music is. It comes to a mournful end and the wistfulness is palpable.
The bad-the more heavily instrumented parts of the piece have the various instrumented parts competing and sounding a little crowded to my ear. This song could have taken advantage of the stereo, but I understand you wanted to have this done before the 25th anniversary of Metroid. As others have mentioned, the drums are stereotypical trip hip hop don't quite do what they might otherwise could.
Overall, it appears to be a song you really put thought into, even if some elements feel rushed (I could never aspire to equal the work, let it be said) and it's gorgeous, one of the best songs I've heard on this site. It'll be listened to as much as Kindred was, I think for me. Any weaknesses is covered by the emotionality of the work and the generally great samples.
