Xenonauts on Mac / Linux!
Xenonauts now has Mac / Linux builds available, but they have additional requirements to run on top of the standard Windows builds due to using WINE.

LINUX:
Once the game is downloaded, you will need to download and install the appropriate version of WINE for your Linux distro. Once WINE is downloaded the game should run normally from inside Steam.

MAC:
The Mac version of the game has to be installed manually. Once it has finished downloading, please go to the download directory (right-click game in Steam >> click "Local Files" tab >> click "View Local Files"). The Xenonauts.zip file contains the game - just extract it and play it, or drag it into Applications to install it.

Both versions of the game are slightly less stable than Windows due to unexpected interactions between the code, WINE and the different operating systems, but we've fixed the majority of the issues and are continuing to patch them where necessary. However, if you have a dual boot machine and it's possible to play on Windows I'd recommend doing that where possible.

Some people are very unhappy that the ports use WINE rather than being native ports. Whilst we understand people would prefer a native port, in this case it is not possible as we do not have access to the engine source code - it's WINE or nothing. Not a good situation, but there's nothing we can do about it.

Please be aware that we have made it clear the ports use WINE at every stage of development and the game is not even advertised as supporting Mac / Linux on Steam (except briefly at the end of the trailer). We're not attempting to mislead anyone about our ports being native, we're simply catering to the people who are happy playing a WINE-wrapped game and think they should be given the option to play the game if they want to.