Rapid2D is the only game engine that is specifically designed to produce Windows 8
The following Tutorials are available
There will be 9 templates each with a basic description released at: http://www.rapid2d.com/forum/viewtopic.php?f=10&t=46
There is an editor and a scripting manual on the download page of rapid2d: http://www.rapid2d.com/downloads.html
Rapid2D will be doing lots more tutorials in both worksheet and video form in the near future and have released an amazing competition where you can WIN £10,000!
If you have already entered, you can login to your team area here.