Midnight Suns is such a batshit insane comic thing, there's no way it could have ever done the sort of numbers an Avengers-type thing could sell.
It has Spiderman in it, but it isn't going to do Spiderman numbers.
I contest that it isn't a puzzle game, though there is a lot of puzzling out the best sorts of moves. Its a tactics game. It has elements of turn based tactics games like Into the Breach and stuff like FFT/Fire Emblem where you have a small set of options for each character every turn. There are lots of things you can customize (eventually) about each character.
Positioning and economy of moves are very important. Picking your actions from a limited set of options (cards) is just a wrinkle on top of the each character can do X things formula. Using cards for that metaphor is a fine choice. I dunno if I think its the best possible thing they could have done flavor wise (since the story involves demons and magic and shit they could have invented anything they want). But it gets the job done and gives you interesting choices each turn.
I also wholeheartedly recommend turning up the difficulty in the game. As you start unlocking harder difficulty levels, you should almost always use them unless you are barely scraping by every mission. The game gets WAY too easy if you don't IMO. But if you do the challenge stays strong all the way through which is pretty unusual for these sorts of games. I will say some of the heroes just don't work well with each other and you can get really messed up by bring a bad group to a tough fight, but I've yet to find anything impossible with some reloads after defeats and employing new tactics.
(I'll test it on my Steam Deck later this afternoon).
