I've been revisiting anno 2205, infamously the ugly duckling of the Anno series of RTS games. I don't mind so much the fact that it's different, lacks customisation and random map generation - I'm bothered because the game is so slow to progress through on challenge settings, and it feels like a game designed just to artificially waste your time; in other anno games, you can always pull tricks to dig yourself out of economic crisis - selling off assets and surplus goods, completing quests for other parties, or taking loans. 2205 is very very confined in terms of what you can do to financially recover in the early game and forces you into a lot of military events.
Sounds like your friend group should play Eve online
Hey, we're talking about past time activity, not getting an extra job.
Though it does actually fit in the theme. Can't remember exactly how many hours i have in it, played it few years and keep getting back to it from time to time.
Bur for the love of god, it's pretty much secondary job, it's not really solo friendly game either. It's almost mandatory to join a corporation or group activities and generally in low sec to make any considerable amount of isk, but that comes with it's own set of obligations and of course the absolute constant threat of PVP.
Of course it's possible to stay in high sec and play solo, but that becomes rather insane grind fest or never even leave the station, but you better start loving EXEL.