@Takashi.0
Undertale bugged me for a different reason. I find it punishes you too much for killing.
See, on my first playthrough i didn’t know you could spare Toriel, so i killed her. Her death was so heartbreaking i decided to never kill again and play kind from then on.
Then my ending comes and… it basically tells me the human world is doomed. So my adventure was meaningless and my attempt at atoning for my sin is irrelevant. I expected a punishment. I killed someone after all, but ending the world? It just really really sucked and made me feel like i shouldn’t have bothered playing.
It got a bit better when i started thinking of that run as the first half of my story, since i played a pacifist run right after. But even there i was still pissed i had to play the same shit over again. Then i got a lame final boss i couldn’t even lose to, meaning i get no sense of accomplishment at the end.