Hi! I haven’t read the other comments, sorry if I’m not adding anything new her: just commenting as I listen. Also, I’m not mincing my words since you’ve asked to hit hard.
Why the hiss? Are you doing this on purpose to add a vintage feel to the song or is it involuntary? In the latter case, surely there must be a way to get rid of it.
The drums have their own reverb (provided by the plugin itself, I’m assuming), which sounds really different from the rest of the tracks, resulting in a lack of cohesion. And even though the instruments are well played, the drums sound 100% quantized which adds to this issue as it really doesn’t feel like a human being playing. The kick is loud and clear, but I think it is too much for this genre, I would bring it down a bit.
The rhythm guitar on the left is too prominent and could use a bit more compression to tame the peaks and make it sit better in the mix. I would also add a little bit of crunch to it to add more grit to the song and make it more interesting since you have several guitars with a clean sound already. In general the guitars overlap too much because they all have a similar sound (which is probably because it’s the same guitar played by the same guy and recorded with the same gear?), and besides the panning choices, they share a similar space in the mix (frequency range, volume). The arrangement is well thought out since you have one strumming rhythm, one arpeggio and one lead, but in terms of sound I would try to give them their own special space more.
The two voices don’t blend well together in my opinion. They sound like they’ve been recorded with different sets of mind. The female vocals sound intimate as if she’s singing close to the mic and with restraint, while the male vocals sound more blunt, sung louder and farther away from the mic. Why not decide on doubling the vocals only on some parts of the song or maybe alternate male and female, and perhaps harmonizing the choruses rather than singing unison? Also, EQ-wise there are some annoying frequencies that should be cut.
The vocal reverb doesn’t sound good, and there’s a bit too much I think. It makes the lead vocals unclear even though they’re quite loud. I would place the guitars deeper in the mix and bring the vocals forward.
I’ve only mentioned what didn’t work for me but there is also a lot that does work.