Very cool. I did a game called Run and Shoot that I started using the UDP Datagram Socket sample. Will be checking out the methods used in this one, I found UDP to be very unreliable on some routers, like toss it in the garbage unreliable not just some lost packets here or there... Was thinking of doing SignalR but would rather not have to stand up a server and was worried about latency.
W8 Game board -
WP multitouch game controllers -