>>529274698
Not necessarily. Penumbra is the point of a shadow where it's a blur between light and dark.
Referenced also by the post Toby made back in the summer of 2011 (the edge of the shadow where reality and dream meet).
I think the ending of Deltarune will have some element of the dark world and the light world colliding. Blurring the lines between the two.
How this happens, with what we know of the mechanics of the world so far, I have no idea.
But it seems like the thing that Toby dreamed about.
I wish I had an intense fever dream telling me the ending to MY dream game...