There's nothing too racy. One card is of a woman with bare shoulders; an adult can infer that she's naked, but it's not a sexualized pose (it's meant more as a Lena Dunham confessional kind of moment). There's no overt violence in the game; there's one card ("Grizzled Action Hero") with a man firing a couple of guns and clips flying everywhere, but you don't see what he's shooting at, and there's no blood or guts.
One ad has the name "Illicit Illana's Illuminations", but again, there's nothing really overt. We will only have art for that ad if we hit a stretch goal, and if we do, it'll hint more than show. There's another ad called "Clarence's Clearance Firearms."
And there's a card called "Always Dies in Everything", with a guy who's been stabbed and shot with an arrow, but it's more cute and cartoony than nasty or gory. You can see that card on the campaign page. There are a few other cards showing dead bodies that are at about the same level of cartoony violence as the "Always Dies in Everything" card (and of course, it is the same "Always Dies in Everything" character in each one.)
That's the worst of it; I think it's safe for most kids 10 and up. There's some humor, but most of them will be able to handle it, and if they're good with middleweight games like Lords of Waterdeep or Stone Age, they should be fine with this game.