There's also Zero-K on steam and it has an actual campaign. Last time I checked BAR had none, but it was on the roadmap

You’re right - it’s not a campaign as such - it’s a set of scenarios (currently 22) in increasing difficulty. I haven’t played for a while after getting stuck but checking now I got stuck on the 5th scenario - even worse than I thought. :)

I played Zero-K several years ago and it didn’t stick in my mind as much but maybe worth revisiting it - thanks!

Reading about it seems to suggest that it’s even deeper in terms of strategy and tactics so I will probably struggle even more. :(