No the game is also fully playable on linux via Proton (About other platforms I have no clue)

If you get it working. They don't seem to have an own website, the publisher links to Steam as the only place to purchase it, and Steam says it's only supported on Windows. Surely you can work around it with VMs, emulation, or other solutions, but sadly the creator declines to support that

Excellent news, I can play the game on my Steam Deck with the on-screen keyboard!