Doesnt Undertale's Genocide run "problematize" being a completionist and JRPGs? And people love that shit.

I would say that it subverts the general jRPG game loop, not problematizes it. It turns the concept on it's head and asks people to actually examine what they're doing, why, and what kind of narrative it creates. It doesn't mean there's anything problematic about jRPGs as a concept.

I have the same criticism as I do of Spec Ops - All player choice in games is fake and severely constrained. You can only do what the devs let you do, and in almost all cases that's means doing whatever the most obvious thing is. Often to the point where interactive objects are painted red or yellow to highlight them in the game environment and make it clear what action you must take to advance the story. Games that try to gotcha the player with "Ooh look at you, you did a bad thing! You're a bad person!" generally fall flat bc the bad thing is the only action the player can take to advance the story. It creates a situation where the player is being scolded for advancing the plot in an entertainment product where they have no agency. Having no agency, they are as such not culpable for their actions. In fact they are not acting. They're the audience in a performance with superficially interactive elements. They are entirely at the mercy of the developers.

When Spec Ops says "Actually you're a bad baddy because you did the murder thing" they're putting the player in a position where they're being scolded for trying to enjoy the product. What, exactly, is the player expected to do? What is the "Good" or "right" choice. The game doesn't have a "Go AWOL" button or a "refuse to fight" button or a "frag your officers" button. If you want to continue to play the game you have to go forward and do the atrocities. You don't have a choice.

I think undertale is more effective because you actually can choose not to fight, there is a plot where the player doesn't kill everything. Because the player has a choice they can actually look back on their decision to fight everybody and say "oh, I had (very limited) agency here. I decided to fight because I thought that is what was expected of me and I didn't consider having other options."

But it's only somewhat effective because again; Players can only do what devs allow them to do, and for the most part the only thing you're allowed to do is the most obvious thing. Moreover, as an entertainment product, as a game in which you are supposed to engage in play, the player can and should expect to be rewarded with at least interesting outcomes for exploring all options provided by the developers. Once you've done the "good" run a lot of people like to go see what the alternative outcomes were and how the story changes if they turned left instead of right at a critical juncture. Since this is all, by definition, play, assigning it some kind of moral weight is rather assinine. In play people assume roles they might not otherwise explicitly because play isn't real. It provides an imaginative chance to consider options you wouldn't necessarily consider in real life, to perform ideals and beliefs, to screw around, to experiment and explore.

When Devs put the player in a situation where the Devs are asserting that the player has done something wrong, rather than the character, they're essentially scolding the player for following the script or turning the page. "If you just closed the book and put it down none of these bad things would have happened. You're an immoral person because you take pleasure in the trials and hardships of these explicitly fictional characters".

I would say the people telling you that you're bad because you explored all the options in the game have a very immature understanding of morality and a very bad understanding of the underlying rules and theory of game design. it's a game. None of the characters in it are real. They don't have thoughts or feelings. They can't experience pain or suffering, nor can they experience joy and love. If the character talks about being harmed or upset, if they scream when the player attacks them, it's because the devs intended them to, intended for the player to do these things to see what would happen.

This has been a constant source of social strife for, as far as I can tell, all of human existence. Whenever a new medium for story telling is developed moral scolds scream from the rooftops that it will destroy society, ruin the sexual morality of women, and turn men in to murderous beasts. It really doesn't matter what it is; Tik-tok, video games, television, radio, movies, rap music, opera, stage plays, novels; A certain faction of society always claims that fiction will somehow destroy the morality of the people and turn everyone in to debased hedonistic monsters who know neither right nor wrong. And they're always wrong. It always turns out to be an unfounded combination of a reactionary hatred of youth and the accusing party projecting it's own inability to distinguish between fiction and reality on others. My observation is that the people who condemn play and imagination most loudly are themselves incapable of either. To them any interest in or enjoyment of a story demonstrates real and enthusiastic support of the concepts in the story and the actions of the characters. They don't seem to be able to grasp the idea that people could read about (or play) a character doing something bad and recognize that the story is fictitious. Whether it's moral watchdogs screaming that FPS games will turn kids in to school shooters or religious freaks screaming that D&D players will sell their souls to satan they're very consistently wrong.

It's basically people screaming "THE CURTAINS ARE BLUE" at the top of their lungs, but instead of being unable or unwilling to see nuance and metaphor in storytelling, they're unable or unwilling to accept the idea that when people play games they are aware of the distinction between fiction and reality.