The first level of MegaMan x and good springs in fallout: New Vegas are really good examples of how to convey info to the player about how the game works and what you can do without pulling you out of the game itself into a separate tutorial
Absolver might fit the description, 3d fighting game but you learn the moves by blocking or dodging then defeating NPCs and PCs. It’s not super long unless you try to learn all the styles and moves or I think they added an infinite dungeon, not sure how good that part is since they added it after I played. But even if you don’t like the PVP the single player learning the moves and defeating the bosses and big bad at the end is really fun.
A bunch of retro games have good couch co-op support & the steam deck can emulate pretty much all of them
Zombies ate my neighbors, smash TV, 2-d brawlers like TMNT turtles in time, double dragon, and streets of rage, Goldeneye, toejam and Earl, bubble bobble
I’ll go with some classics if you haven’t tried them yet. Planescape: torment is a really engaging crpg if you don’t mind old graphics and dig lots of lore and dialogue. Morrowind if you prefer first person for another old school rpg with lots of stuff to discover in a weird surreal environment. Dwarf fortress sounds like another older one you might be into too.
You could try the original version, they released it for free and the pixelation may help make it feel less disorienting. Or when I used to play some games on the psvr I’d have a ginger ale or something with ginger in it to help with any disorientation nausea.
Do what you think is right, but spend some time to consider whether you want to reward someone or some organization with your hard earned money if you consider what they are doing immoral or bad.