It’s still very early in its DLC cycle. There’s Voice of the People which is good for the political metagame, adding agitators who help push legislative agendas, and a Brazilian content pack that I haven’t bought yet because South America is so painfully slow to industrialise. You’d be fine to just get the base game and maybe buy Voice of the People on sale.

I don’t know how its linux performance is. The game gives a good representation of base and superstructure, but only in an abstract sense. You see the transition from the remnants of feudalism to early and middle stage capitalism, all tied to the material conditions of your citizens and how their ideology ontologically impacts their response to things. It makes you viscerally hate groups like landowners by juxtaposing their desire to hoard money with your need for tax revenue/legislation benefiting 90% of society. You get a good sense of what separates the petit bourgeoisie from the Ancien régime of the larger bourgeois factions, what separates the proletariat from the peasant, and how your relationship to the means of production shapes you.

it officially supports Linux