Caveblazers Together

Links: Steam page · blog post · manual & FAQ

Caveblazers Together is an online multiplayer mod for Caveblazers.

It allows to play the game over the internet with up to 4 players at once.

This version can be used with both Steam version of Caveblazers and DRM-free releases (GOG).
When used with Steam, the mod uses the Steam backend for networking
Otherwise it can be used with port forwarding, over LAN, or through VPN services (ZeroTier, Hamachi, Radmin, etc.)

It supports vast majority of base game's features as well as some specific to it - such as chat and chat commands.

Please keep in mind that this isn't something that the game have been developed with so you may encounter minor oddities.