Marvel Tōkon: Fighting Souls has been highly anticipated for some time and that's partly because it's from Arc System Works, the company behind the likes of Guilty Gear, Blazblue, and Persona 4 Arena. Yet Steam users are disappointed in its opening few days. That's because despite many praising the game itself, it reportedly has a litany of tech issues.
The game currently sits at a 'Mixed' (56% negative) rating on Steam with almost 1,600 reviews, and it appears to have around 10,000 concurrent players on SteamDB at the time of writing. Considering it's a $60 game, that's a pretty sizable number of people.