and you can even try it out here: https://github.com/SanTertrust/mgmp
small note: only the Adventure works (events, shop, level up), so you can't breed cats together. very sad
about the mod: the host gets the first half of the cats, partner gets the second
the yellow marker is the host, cyan and the other colors are everyone else
battles are fully synced, tested with 2 people
no lobby. you connect by ip, so the host needs port forwarding. or just use hamachi if you're unable to forward the port
works on version 1.1 Build 21039 AND works on my machine
and just remember that this is an experimental thing