No, this isn't some sort of Rule 34 thing. Love Letter isn't always about courting someone for romance. So, when you reskin it for a Marvel setting, you can simply swap it to the Infinity Gauntlet and away you go. That's what we've got here. If you've liked the game but didn't really like all the lovey-dovey stuff, this might be the version for you.
From the post:
The Mad Titan Thanos is on a crusade to find the six Infinity Stones, but a team of mighty heroes has assembled to stop him. In an epic battle for the fate of the universe, whose hand will win the day?
Introducing Infinity Gauntlet: A Love Letter™ Game, a new one-versus-many twist on the bestselling card game set in the Marvel Universe. Play as Thanos himself and seek ultimate power or assemble beloved Marvel heroes to stand against him. Act decisively—your choices will decide the course of history.
Preorder nowonline or through your local retailer!