(This might be a bit long, so I'll put a TLDR at the end, feel free to skip to that if you wish to)
Now that I've had some time to listen to Roses a few times and form an opinion of it, I've got to say that honestly, I'm not a fan of it, which is a real shame because I so desperately wanted to be. Now, just to preface, I am categorically not saying that Roses is a bad song in any way, because it isn't, but there are a few things that I don't like about it.
My main issue is the direction that the band has gone in with the song. I'm all for artists switching things up and trying something new, but at the same time, it's good to keep that core DNA that gives an artist their distinctive sound, and it feels like Roses is a departure from that. The best example I can think of is Screen Violence: they introduced a much darker vibe to their music while still retaining the CHVRCHES sound, and it was a solid balance of the two. I was kind of hoping for a sound similar to what they did to 'Over' a few years back for the new song.
In the song itself, I will say that I like the verses. They have good flow and the lyricism is great too. However, I'm less of a fan of other elements. I've said before that I'm not big on the bridge section, and I also feel as though the outro goes on for a bit too long (though this could just be leading into the next song if it starts in a similar way). I also noticed in the intro that there's a kind of 'pulsing' effect with the music, which does help to give it a dark vibe, but at the same time, it does feel slightly jarring.
This is absolutely no disrespect to the group, the song is honestly good, but I'm just not a fan of it. I wanted to be, and I tried to make myself like it, but it doesn't click with me in the way that their old material does.
TLDR: I'm not a big fan of Roses: vibe, bridge and intro melody are my main reasons.