Read the game-specific operating-system requirement
The relevant Steam information is the game's own system-requirements section. The retrieved listing specifies Windows rather than a native Mac release. GOG's game-specific compatibility information independently identifies Windows for the full game, and its separate demo listing does the same.
These entries answer what the collected stores advertise, rather than proving that a future Mac version can never exist. The researched platform coverage does not establish a Mac port either. This guide therefore reports no verified native macOS support as of the research date.
GOG Galaxy is a store client, not the game
A store can offer its launcher on Mac while selling individual games that only support Windows. The GOG Galaxy Mac download link concerns the client software, not the operating systems supported by Tenebris Somnia. Use the game's own compatibility entry instead of treating the website's general download controls as a port announcement.
- Check the operating-system field on the full-game listing.
- Check the demo separately rather than assuming identical client compatibility.
- Do not treat a general Mac launcher download as a native game installer.
Untested workarounds are not supported instructions
Wine, CrossOver and virtual-machine compatibility were not tested in the supplied research. There is no verified installation procedure, settings profile or supported troubleshooting route for those methods here. Publishing a sequence of guessed steps would make an unsupported workaround look like a documented way to play.
A separate platform may be a better research topic than a speculative Mac fix. The Steam Deck guide addresses the collected Verified badge without pretending that it proves macOS compatibility. The demo guide identifies the official Windows demo listings, while the release date guide covers the announced launch.