We already kinda had such a game, and the results are what anyone would suspect.[...] Wonder what a class would look like if this game had multiplayer [...]
There was an awesome FPS shooter game called "The Ship", that was like multiplayer Sims, 'cept players had to covertly assassinate each other with a shuffling list of weapons to out-earn all other players for a high-score by the end of the round. "Was" is unfortunately true of this game's status, legal contract prevents anyone from updating the game or making a direct sequel.
How's that work? Manage your needs to eat, sleep, shit, bathe, and socialize all while hunting your quarry as you evade your hunter without getting caught or murdering people carelessly. You tend to die if you don't fulfill your needs. Yes, even the weirdly harmless-sounding bathing deprivation will kill you in cartoonish fashion as flies consume you.
What's up with those last 2 caveats? First if you get caught you get fined money, and money is your high score so by getting caught doing anything incriminating like attacking or holding an obvious weapon in your hands you start losing, though holstering hides weapons and you can carry 2. After being fined you're in this map's jail, unable to hunt your quarry and easily trackable by your pursuer who can shoot you through the prison's bar gate door or a window if you're careless. Or he can simply wait in front of the door you'd exit from. Or he can even do crime on purpose to get in, be lucky enough to find a shank, then kill you right there. So sometimes purposely losing a bit gets you closer to winning if you're smart.
You can stay alive by changing your disguise regularly to throw off the tracker for a bit before it relearns your last disguise and location. You are also permitted to kill your pursuer as your quarry is permitted to kill you without a score malus. If you kill an innocent who is logically unconnected with you, you lose money.
It turns out stupid players really do deathmatch and lose for the hell of it. Actual deathmatch wasn't popular in a game that was so unique, though as a game this old and unique was also really fuckin' dead online the wannabe deathmatchers just hop into a hunt game and ruin it anyway.
So... yeah. If this game had multiplayer you'd bet trolls would gank you to kingdom come repeatedly. This is why we can't have nice things.
Although I swear the above could be made into a VR Chat modded game mode. I'm surprised I've not heard of demand for such a thing but I would not be surprised if it already existed or was currently a project in development.