Starting from just now, AirMess is also available on Desktop :)
You can now play it both on a Windows RT device, Windows 8 using the Modern UI mode, or Windows Desktop on both Windows 7 and Windows 8.
Just make sure that you have the prerequisites for Windows 7 :)
- Platform update for Windows 7 SP1 and Windows Server 2008 R2 SP1, which update the DirectX API
- .NET Framework 4.5, that the game uses
Have fun, and feedback highly appreciated! :)