The current pre-release of the client ("pioneer" in the version) is only compatible to itself. So you can only play with other testers. Please be aware!
@axel12 This was a joke.
The point was Square Enix is sitting on a mountain of franchises and IP, but never used any of them. Like a dragon just sitting on it's gold. People WANT a Chrono game, it gets a 9/10 rating, but its been 25 years and they still don't give a shit. They just churn out more Final Fantasy crap.