What is the theme of Undertale?

Megalovania.                  =/       Lol I have to have 20 letters

One of the key themes of undertale is the notion of preconceived ideas, and the awareness that all of them are not necessarily right when you step back.

illogical logic there is a corridor between the garage and the balcony. illogical logic i rent an apartment with four rooms: a kitchen, a bedroom, a living room illogical logic xavier starts a new job in another city. illogical logic the rents in this cellar are really too expensive. illical logic barbara's studio has a garden. illogical logic