Sunless Sea: Now with Steam trading cards and badges!
Play Sunless Sea to collect trading cards, and trade in complete sets of cards for badges. Each badge features a Correspondence sigil - with its definition.
I can’t give this game an unequivocal recommendation, as there’s things about it which are disappointing to me (review forthcoming, I swear). But it is a really neat and unique experience, easily worth trying out for free to see if it’s your thing.
