GenZedong

Personally I don't think it's very interesting to approach the game as critique of society directly, maybe because of the RPG mannerisms of kings and queens, but I think the game does have something interesting to say viewed as a media critique. What I got out of it was this postmodern parody of the narrative tropes of video games (and other media as well) wherein you are a cosmically anointed ubermensch going out to do something and you'll kill anything that gets in your way without a second thought of its interiority. So as a foil look at Hollowknight which is pretty much exactly that narrative structure, and while there are a couple bugs with interiority most of them are othered quite explicitly through a mind virus. But beyond even that there's creatures that are just set dressing like the birds, which you end up exploding without even realizing when super dashing across a map. In HK these moments are normalized through a lack of commentary while the whole point of UT is problematizing this dynamic by creating a sense of interiority in these small background creatures whose life is at your mercy. The frame of this is individual ethical choices which same may call a liberal branch of thought, but I personally think it's worth examining your personal ethics.

Interestingly, the subversive narrative of the true pacifist route not only includes pacifism which is obviously anathema to serious political leftism (but again, I'd say is a good pursuit as an individual), but this narrative also includes building together a community and transforming the society of the game. If I remember correctly it's maybe a restoration of monarchy (ew), but the narractive structure of sublimating your individual interests in order to help others and reshape society is quite radical. And the salient point: UT implicitly makes us question why this narrative structure is uncommon compared to destructive quasi colonial ones of other games. So then the question posed is not "why is society not like undertale?" but "why does society create games with violent individualistic narratives?"