Wow, a networked multiplayer game in a jam is bold, but awesome job getting it done and working!
In the future, if you do another online game, you should probably have some sort of demo/tutorial mode for people who can't hunt down someone to play with or don't know they can open the game twice to demo out ( that's what I did ). It's really cool once you get it going, I absolutely loved the sound effects for placing the blocks, definitely got a good chuckle from me :)
Good job!