If I'm to be a bit Simon Cowell about it:
Intro - guitar seems out of time and tune with the backing.
The layered sound seems a bit like they don't belong together - kinda comes over like a bootleg/mash.
Levels are a bit odd - backing overrides most in the first two minutes.
Build up at 1:40 is more my thing but when it first comes in seems that same layered disjointedness.
However 2:30 onwards really quite enjoy it, love the subtle orchestral bits and the licks. I think it fares better for losing the vocals - though when she comes back in for the reprise it's sounds like everyone's now playing from the same songsheet and is top notch.
So, not trying to be harsh, just the first perhaps two minutes don't do it for me. It gets better and then just as I'm starting to enjoy it, finishes
However, it's bloody impressive if this is something you're involved in. Take my hat off to anyone who can make/ produce music. Nice one!!!