Really interesting game, I've seen quite a few tethered games of this nature but none multiplayer, none 3d, and absolutely none with such a rubber band tether like this one lol!
I have to say while it is a cool game, in practice it just feels like you're constantly fighting with the weird rubber band tether and trying desperately to not fly off the map. I'm not quite sure what could be done to fix this but it's worth looking into.
All in all though a really cool concept and I'd love to see what you do with it in the future!
Great job friend :D