Have it on ITCH. Bought it on Steam.
Using Steam Deck, and Protontricks to apply patch to the game.
Unfortunately, Reconstruction patch 2.15 from Saikey store always "failed to patch" on "applying content patch " step to "Game_Data\data.unity3d".
Using WINE instead of Protontricks howether worked.
Unfortunate, as it require WINE installation, custom permissions for WINE to access game FILES, and running patch in desktop mode.
Thankfully it works in the end, it's just a little too many steps for casual user.