Really nice submission! I love the leitmotif you used throughout, it gives the soundtrack a great authentic old-school feeling. My favourite track is probably the battle theme, definitely reminds me of some of the classic JRPG battle themes like those found in the first few Final Fantasy games. I also love the cinematic trailer theme, a clever way of showing off your excellent orchestration skills while still feeling cohesive with the rest of the soundtrack.
I have one very tiny nitpick, I would have made this an NES game rather than a Game Boy game, as the Game Boy sound chip has some weird quirks and extra features that don't make an appearance in this soundtrack (for example a custom wave channel instead of the triangle channel found on an NES, and the ability to pan sounds to the left or right). I realise that you might not be trying to fit with any specific console's sound capabilities, and really this is completely inconsequential, but I just thought I'd point it out.
Overall this is a fantastic entry, great job!