I replied on the YT vid, but YT isn't really the place for in-depth feedback. Had no idea you posted here too, but I love it! I'm also the guy who wrote the source, so I'm a little biased
It sounds pretty heavy in the lows/low-mids, especially with the combination of the low piano and low strings. I think you're getting a little mud from the two together, and it may be to the track's benefit to either make some concessions with part writing when both get a little busier, or to reexamine your EQ on the two instruments (possibly both). I love how the two work together, especially the lead cello stabs, they're just fighting each other really hard right now in the lower range. You may also be getting some unwanted compression from the drums, particularly the kick. You can hear it on the higher piano notes especially, they're pumping just a bit. A common thing with kicks is to have the subs boosted REAL high without really being able to hear it, since that's a range that typically gets fairly bad response in most headphones or speakers (if you don't have a sub). I LOVE the drum groove itself, it's exactly what it needs to be. I'm grooving all the way through, so no complaints on the part-writing there either.
Hope that helps a bit! Again, love all the extra nods to the Melee theme you snuck in, and thanks for making the 'mix