I was trying to get as close to the original as possible while leaving out things I couldn't put like the pads/drones. Hmm good point about the drums. Yeah I was trying to figure out volume in the tables and also the Exx command, I didn't quite get it so I decided not to fool with it. Wasn't sure if they operated like velocity in trackers like sunvox or what.

Some folks don't mind for organic time lines like your attempt. The notes being absolutely perfect timing could help as it's a cover, but for the same reasons if thats what you were going for theres no reason you can't have a cover that contains "timing issues"

It's all down to what you're trying to achieve.

If you're really worried about timing, grab some midis, load them up in your favorite daw, take a peek at what the real notes look like, and transcribe that to the gameboy. There no point in reinventing the wheel if someones done the work for you.

As for my personal tastes, I feel you could fill up the silence but not allowing the notes to cut off so soon and so suddenly... Sometimes I like to let my notes ring out at like volume 1 as sort of a filler reverb (not exactly a reverb) it helps fill the dead air so to speak. Volume automations can turn an otherwise bland mix into a dynamic wonderment if done right.

All in all I'd say you're off to a great start. I'd be cool to hear some drums accompaning this song. For cover songs that don't originally have percussion, I take that as my opportunity to throw in my personal creative touch. It will give it more of a personal identity as your creation.

I tried to make a gameboy version of the Metroid Prime level music for Phendrana Drifts. This would be my first cover song, well that's not necessarily true (some short zelda loops), but this is the first time I went through a whole song.

The choir melody section and the piano solo bits and a little after that probably doesn't have quite all the right notes and maybe some timing issues.

The song is kind of hard to do right without that sense of atmosphere that's in the original. I grabbed a video from youtube and listened to the song every now and again and tried to get the notes by listening through several times (I just play by ear).

Hopefully I don't murder anyone's ears. Here it is: https://db.tt/nBG90FYY
Ignore the small sound at the beginning before anything really starts, I recorded it with audacity on an emulator and I'm not sure why it did that.