Hey there :D Dropping a review as requested - you should probably ignore the score/10 that I give, because I find those a bit arbitrary when it comes to analyzing and critiquing to be perfectly honest.
I'm going to start off talking about your mixing. I can hear your kick fairly well, though it has no high-end presence, so you might want to consider EQing it differently or choosing a different sample; though I get the impression the high-end on it can't be heard because it's being masked by the amount of stuff going on in the chorus, so maybe you should be sidechaining your arps to it or something - it might even sound cool.
Your leads and main synths are pretty clear, enough so that I can tell what's going on melodically - they mesh with the song pretty well, and you're filling the spectrum pretty evenly! I feel your mixing is probably the strongest part of this song, though I would have appreciated more brightness in the hats (some sidechained noise would achieve a similar result.) I think the bass could have less presence (especially on attack) but I do like how it sounds.
Despite everything being audible and pretty evenly balanced, I think your mixing suffers in an instrumentation sense - you've got a lot of different things going on up above 1khz, and at some point everything becomes a bit muddy. The pluck chords around 1:47 could honestly be an octave lower (take the lowpass off them gradually a bit, let some harmonics come through) and they'd probably fit into the mix a bit better. One thing I want to praise here is the little blippy plucky squarey arps in this bit, because their transients make them very audible - more so than the main melody, though.
Your mixing is pretty good in the other sections, there are a lot of little things I could nitpick out but many of them are a bit subjective and it would be tedious to read :P
One thing I will say is that the reverses that start after 3:13 are too loud, and too aggressive in the high-mids. They're a nice sound, but they stick out too much.
Onto mastering, there's one big thing I want to talk about - gain structure. Your song has a lot of headroom (it's at around -14RMS at its loudest) and while headroom is usually good, you're very clearly squashing the mix a bit (it's extremely evident at points like 2:00 minutes in, and during the subsequent chorus where I can hear some ducking.) Again, this isn't even a bad thing, but your song is very quiet for having this kind of sound. I'd guess that this issue stems from the mixing process, but that's only a guess. Either way, you can get a lot more volume out of your song for half the price in my opinion.
I don't know how you handle the process, so I can't really help much there - everyone does it differently, and there's no wrong way, but it's easy to make mistakes. If you have any specific questions I'd be more than happy to answer them :P
Sound design-wise you're pretty good - there are no points where I had any big issues with anything. I like your bass, and your plucks, and the bell lead is pretty cool! I don't like the formanty sound you've got with it in the first buildup/chorus that much, but to be honest it's pretty appropriate and works quite well. I think you could be using a better flute VST/sample, but the idea of a flute clearly works well. You kept it simple, and I like it.
Okay, so on composition - I haven't heard the original at all, and there are parts of your song that I like, but there are some others that I find a bit jarring. The transition at 2:33 comes to mind; there's nothing leading into it and it comes quite suddenly. I like what it leads into though, at 3:13. This part appeals to me quite well for some reason :P
Starting from the start: I like the chordless intro and how it leads into the chorus. It's a tried and true tactic :P the song stays pretty solid when you start introducing other sounds, too! I like the melody. I think it falls apart a bit around 1:32 with the flute though - again, the transition to the breakdown is a bit forced and I don't think the melody works well with your chords. Unfortunately of all the NGADM judges I'm probably the worst at communicating musical concepts (no formal training, I make EDM :P) so I'm limited in how I can describe exactly what I'm referring to here.
Anyway, props on your transition around the 2:00 mark! You worked your way back into the chorus really nicely here and I think it works real nice. The next part I'd like to talk about is at 3:45. While this works nicely as an outro, I'm not a fan of how we got there. The feel of the song is very dramatic beforehand, and immediately switches into a calm state (the instrumentation is good at reinforcing this though, which was nice). The outro itself is pretty sweet though, good use of noise, the low bells are awesome. The very end of it is damn spooky actually :P
Overall I think your mixing is pretty good, though some aspects of it need attention, your mastering could be better (though honestly despite what I've said, you avoided a lot bigger problems), your sound design is good, and the composition is alright, with attention needed to transitions perhaps. Again, maybe I would be sorted out if I'd heard the original; but I'm trying to judge this as a piece on its own.
I tried to be as objective/critical as I could, which is why this review might seem unkind - I hope it doesn't though, because that's not the idea. Keep going at it man :)