Multi-puck Game Howto?

I'd look at maybe using advertising? You don't need an active connection to other Espruinos to transfer data - it could be as simple as:

NRF.setAdvertising({},{manufacturer:0x590,manufacturerData:"yourdata"});
NRF.setScan(function(d) {
  if (d.manufacturer!=0x590) return;
  // otherwise use d.manufacturerData
});

This would increase power usage, but you could always use NRF.findDevices(..., 500) every few seconds so you're not listening all the time.

The nice thing about that is there's no limit to the amount of devices you can have.

There is a Bluetooth Mesh spec that hopefully will get implemented at some point soon, but it actually works in a very similar way to the above code under the hood.