Are there any single player campaigns set during the Strogg invasion of Earth, prequels to Q2? I can't understand why there wasn't a single player equivalent to Enemy Territory: Quake Wars. Like Wolfenstein: Enemy Territory and RTCW. Or maybe I'm wrong? Maybe there is a mod, a campaign or mapping jam that does just that? I loved seeing Ruined Earth (and Moon) in Call of the Machine and I want to explore more of this epoch.

We - as in Map-Center - are planning to do just that, but sadly, that's a long way off.

Officially the closest you get is Quake Wars. There are "campaigns" but as you say, not single-player.

In terms of non-official commercial products, Oblivion technically takes place during this content.

As for player mods, don't know of any off-hand.

There is a mission in Call of the Machine called Operation: Ruined Earth.

I'd throw money at this personally

Thanks, I'll check out Oblivion for sure.

No need, my friend, we do it out of love for the game. However, if you're on Discord, we could always use more playtesters!