Dungeons and Dragons features thrill and wealth-seeking "adventurers" exterminating and stealing from creatures already pushed to the fringes of the world by the dominant humanoid society. Undertale demystifies and humanizes the victims - putting the focus on their disintegrated, desperate, and tragic world as a generic "1980s white Western kid" explores what's left of their lives. While a traditional RPG features the psychological reality of a dominator viewing his victims as terrible creatures who deserve to die (and have all of their wealth transferred to him, as payment for the trouble he's gone through, and in order to "level him up" to achieve whatever personal ambition he desires), Undertale appreciates the reality that the people outside of mainstream society are the most colorful, personal, and humane, since the very act of being marginalized makes them no longer beholden to imperial or corporate interests, allowing them to be... human, for the first time in their lives. When they become human they become strange, resulting in the varied and wonderful creatures depicted in the game.
So while Dragon Age has "kills" as a triumphant scorecard (the same way a womanizer treats "lays", a pride in conquest), proof of the cleansing of the world, making it safe for the hegemony of the dominant society to continue unabated, in the same way as a drug dealer might "cleanse" a section of the city of a rival dealer, in Undertale the kills statistic feels like a personal failure of the player - since the victims aren't treated as savage monsters whose only value is as a corpse the kills feel more like what they actually are in reality when one kills a marginalized person - the murder of a human being. I find myself worrying that my weapon does *too much* damage, which increases the risk of accidental murders. Ask a player of World of Warcraft or Dragon Age whether his weapon does too much damage and he'll assume you're a lunatic. He won't even comprehend the basis of the question - obviously weapons can't possibly do too much damage because the only value of the things the weapons strike is the transferring of that thing from living to dead and the resultant gain in power to the murderer. Err, rather, the "hero", to use the hegemonic term.
We, as players, know that our main character is immortal within the game world, due to the reload function. We also understand that for the fiction we are experiencing to work in the way it's intended, the "monsters" we face understand *themselves* as mortal - they think they are existing in reality, are flesh and blood, and have only one life. So while our own murder of them is trivial - they exist in our reality as mere code which we can efficiently bypass to continue the narrative and "hero's journey" of the game, to them their fight with us is a life-or-death struggle for survival. The usual way to treat THEIR CONCEPT OF THEMSELVES AND THEIR OWN REALITY is to utterly disregard it - obviously they are mere tools of our own enjoyment - we're the ones the game is made for, not them, and as such their view of themselves merely serves to maximize our own enjoyment - it helps the narrative that they believe they exist, and their desperation to fight off an immortal, super-powerful enemy merely makes the trivial bypassing of them more "real".
This creates an interesting and disturbing and ridiculous dilemma. The "monsters" who only exist to "service" the main character through loot and XP are the ones who believe in the reality of the game, while we, who see the "truth", appreciate it's triviality and thus the triviality of everything that occurs within it, including genocide. The main character, who flits through the world as a conduit for the player to gain new knowledge through exploring this artistic construction and who treats all entities only in terms of their effect on his own exploration is completely unreal within the fiction of the game - the same way such a creature in our own world would be uncomprehended by us. We would be slaughtered, or not, or whatever, by a creature who disregards our own conception of ourselves in favor of "the truth". Our terror at encountering him would be great and our only relief would be had when he tired of us and moved on to bother another world.
When we're playing a game it frequently feels like we're not really a part of the world - the *monsters* are the world, we're just visiting, and in 20 hours we'll be done visiting and move on to another artistic construction, while the code, the monsters, will STILL BE THERE.
