Given the current state of the game (the one we keep passing around between client and server), I don't think Erlang is a bottleneck in performance for us, and it won't be in the near future. Keep in mind this state is not that huge and it is yet not distributed, so it is totally possible that at some point Erlang will slow us down. I will keep your comment in mind, thank you!

Edit: currently with the game running at 60fps, there is no bottleneck from the server side. And we call it every 16ms! I should also mention that Erlang's choice has a learning purpose; we want to try to use the game as a way to learn more about OTP and the BEAM.