Dark Ages is more complicated in terms of actual card mechanics. Guilds is more complicated in terms of metagame.
I'm not sure what you mean by "metagame".
Decisions and tactics involving anything beyond just how to effectively play cards - managing your coin tokens, which cards to buy in what quantity, keeping track of score, etc. The game of playing the game.
That's not metagame. (Except maybe point tracking).
AJD's examples are metagame. As wiki says "In simple terms, it is the use of out-of-game information or resources to affect one's in-game decisions." Menaging tokens and buying cards are well within the game.
I guess I meant something more along the lines of overarching tactics and strategy, then.