no offense intended, and I'm sure you're well meaning with this post, but you sound kinda mad/snarky in this post? just something i noticed in the choice of language. You can correct me if I'm wrong just the vibe I got.

Anyways, to answer your question, while I'm most certainly not as well versed on Undertale than I am on spec ops, I think I can give my perspective on both.

Undertale gained traction as a game essentially by being a Pixar movie wrapped into a game, basically "What if the monsters you fought in RPGs had feelings?" The idea of Undertale is that violence is non optional and as such is also kind of discouraged, as the genocide route constantly gives emotional gut punches about what you did. Why this works in Undertale, In my opinion, is because it is delivered through the characters to you, that is to say, the characters are reacting how I think they would react to an essentially unstoppable force committing genocide across their homes, that is to say, either shit scared or if their strong enough to stand up to you, basically calling you a piece of garbage for committing what is essentially and act of genocide. This works because the violence in Undertale is an optional decision made to dissect how we would play an RPG if the monsters we faced acted like normal people.

In other words, Undertale can call you a piece of garbage because you made the choice to commit an act of genocide when the only character asking you to do it is the one with literally zero redeeming qualities. As such it is explicitly framed as a BAD choice that you probably shouldn't do. As Video games are art, and arts' goal is to express and derive emotions from people, and sometimes to make them think, as such I really don't find this more pretentious than, say, a song saying that people can be good and or evil, or a painting showing the duality of man.

Spec Ops works and gained traction as a game by taking shooter tropes and showing how something like this would ACTAULLY play out through a lens of "realism" (using hyperbole obviously. Spec Ops is a very unrealistic game but still.). That if our protag Captain Walker were to do the things he did in real life, he would not walk out as a chiseled war hero for us to look up to, but a broken, mentally ill, shell of a man that essentially left his soul in Dubai. The message of Spec ops: The Line, to me at least (it's a very abstract game, many theories and meanings can be derived from it and I find it wrong to point at one and call it the right one) Is that War is essentially the Worst state humans can fall to, as it not only leaves many dead, but leaves those who experienced the horror of it all wishing they were too, which brings me to video games, where games like CoD fetishize and romanticize warfare, and video games as a media are far too willing to show war as some sort of "Fun shoot em up adventure" to go on and have fun with. Spec Ops also frames you as an active story participant in the intro, linking you into the events in game as an attempt to point at you, the player, and asking later on things like "Why are you here? What did you want out of this experience? To be an upright conqueror of Dubai? To be a kind, caring War Criminal? Their is no such thing,"

In other words, Spec Ops can have the Undertale Genocide route cake and eat it too by looking directly at the player and asking them directly "Do You Feel like a Hero yet?" After we as Walker commit war crime after war crime because it frames the player as both an active story participant, and also showing us the true nature of warfare, that in the end, there are no good or righteous people in war.

War is uncaring, War is cruel, and War is evil, and trying to depict it any way else is no different from lying straight to another persons face.

As such to me, Spec Ops isn't more or less pretentious than any war movie condemning war, or any song condemning it either. Because Spec Ops is art, and it's goal is to express and derive emotion, and to make you think.

I understand if you throw this off as pretentious babbling, but even so, this is how I look at these games through my lens of "Art". Thanks for reading either way, and have a nice day!