Pillars of Light have been released on Linux after some testing on my side. Tests have been run on Ubuntu with and without the help of Proton.
In addition, the game has been tested on Steamdeck (and it worked amazingly well).
It should be now publicly available for Linux & Steamdeck users.
Please, feel free to reach out if you have any problems regarding Pillars of Light on these devices.
Have a good one !
Narom