I was about to say that I didn't know this track, but I seem to have liked a video of the music, so I guess I can just say I'm not super familiar with it. It sounds pretty solid so far. Love how you arranged that track 3 lead, and the panning in general.
The first 48 measures of Fallen Down are pretty good, notewise. Personally I would have liked the notes to be more a bit more decayed. Additionally, try tinkering around with the frequency as I think you've got the key right, but just not in the right "tune" yet. Jpzarde is also right in the sense that when some notes are missing. For example, there's an additional voice that supports the bass and moves pretty much in parallel with it. In your ORG, however, there is only a bass and no other supporting voices.
Missing notes and detuning aside, let's talk about the second half of the transcription with the Once Upon a Time/the theme probably most associated with Undertale motif. The lead in the original sounds like it uses the same voice that plays the lead in the first half with the familiar "Fallen Down" bit. Thus don't swap out the lead in the Undertale motif to track 4, rather, keep it in track 1. (That or have track 4/track 4's instrument do the entire lead.) Secondly, if you listen to the original track closely, the lead for the Undertale motif decays quickly, not slowly (choose Decay Fast for Notes Volume and that generally makes it sound more true to the original track). This applies to tracks 7 and 8 in that section as well.
From measure 64 onwards, track 1 is also playing in unison with what you arranged in track 3. Lastly, and probably most importantly - the notes in bar 80 to the end for track 1 are quite off. These notes and chords are pretty much the same as the outtro of Once Upon a Time, so use that as your guide.
Regarding the "Can You Really Call This a Hotel" track - again, the notes aren't decaying fast enough in your ORG, making it sound less urgent and off balance. I think some of the instrument choices are fine, as well as the percussion. There's a few notes here and there that aren't quite accurate.