It's working fine for me. I like the improved icons and slightly adjusted layout, and the auto-hide panel feature is great.
Issues with my setup: window title applet isn't yet updated to support KDE 6. I know there's a version on the AUR that should work, but I'm waiting to see if it hits the Arch extras repo soon. My Papirus icons don't seem to be applying, so all my folders are Green but Dolphin's icon itself is blue. I also did get a weird temporary black box when moving a window out of the way from an auto hide panel, and the auto hide causes a stutter when it comes back into view.
1050 Ti laptop running X11 (optimus-manager) through HDMI with lid closed
Calamity is great, but if you've never played any other games, I'd try others before running straight from Terraria to Calamity. If just for a broader experience