>>536262779
I wouldn't bet on it, but it's pretty plausible.
>looks like a grey alien
>extremely capable with science and technology, is the reason the underground has a CORE
>speaks in a way completely different from humans, monsters, and darkners, like he's from another world
>music and sound effects have distinct "sci-fi" sound (seriously, listen to ANOTHER HIM and try to imagine the type of environment that a song with those synths would play in)
>earthbound superfan toby would just have to put aliens in one of his games at some point
Also, darkness seems strongly associated with stars in Deltarune. The "dark" might specifically be the void of outer space.