I just bought this and I don't really know how to run it on Arch. Any tips?

Use appimage or see this thread https://itch.io/t/3173548/arch-linux-zstpkgbuild-package (you can create your own build package by reading around  https://wiki.archlinux.org/title/Arch_build_system )

Hopefully devs don't forget to include a package file for Arch this time!

Thanks, I even read the post but my brain didn't work properly. Installed it and seems to be working as expected.

I just installed appimagelauncher from the aur and it worked from there.

Arch Linux package types are now available through the Itch.io page, consider re-downloading the version suitable for your operating system / distribution.