The Lost Maze for Windows Phone is the same version as Windows 8 and PC/Desktop without some options. The game will work with Windows Phone 7 & 8 devices but I've only tested it on my HTC 8X (Windows Phone 8). If you want to join the closed beta you can send me a message with a valid email address (the same used with your Windows Phone) and I'll add you to the testers list.
The finale release is planned for october 2013.