Okay so I'm not really the most knowledgeable on mixing, but I think you did a rlly good job with this, considering I think with a song like this it'd be tricky to balance it so that the vocals aren't super quiet, but also aren't like, drowning out the song itself?
The only thing I'd say is that at some points the harmonies sound a tiny bit dissonant, if that's the right word? But it's not really particularly distracting or anything and I think it might just be that they're a lil too loud, so I'd say this came out good! ^^
(Again, not an expert on mixing-)