As far as I know, Homeworld 1 and 2 classic (without mods) do not have online multiplayer. So that option to play on Steam with Complex is most probably a place holder, or someother.
You should be able however to use Tunngle (or anyother virtual lan program) to host and join lan games which function almost the same as online games. I haven't tested Tunngle with this version of the game, can't say if it works, but alteast it has dedicated rooms made for Complex and Remastered HW.

HW Remastered version of the game has multiplayer. How stable it is I can't confirm as well, but you need to make a Shift account and then link it with Steam. I did see several games being hosted atm, didn't try joining any though.

Yeah. You can direct connect or lan if you have buddies trying to connect to a match.

On a side note, haven't had any problems with HW Remasters multiplayer.

I also looked into their forums, and it looks like they suggest using tunngle. It's a vpn software that lets you operate using lan settings over the internet. It also helps by creating lobbys for games so people interested in playing together can vpn through it. The goal was to revitalize old games that have lost their multiplayer function.

Yes, it works on Tunngle. Unfortunately, I've not been able to find anybody to play with yet.

When I try to host a LAN game in Complex, even once I've checked the ready box with only one other CPU player in the game, the start game button remains greyed out. There appears to be no way to play multiplayer using classic mods from what I've been able to tell.

I've tried over Tunngle but when my buddy hosts a room I can't join it because it says our versions are different. We both did the same thing to get the game. Our file sizes for hw2.big, music.big and complex.big are all identical.

I haven't found any help on this so far and I'm really hoping to find something about this.

GOGOGO multiplauer.
add me as a friend

themothership.ts3.cloud - TS server for Complex mp, add to heap post please