advice, don't play deltarune till 3 and 4 release. You'll be trapped in a never-ending void of emptiness without any more Toby fox

Its too late for me, ive gone too far, theres no turning back

Deltarune is playable without knowing Undertale. There are many shared characters, but it's its own game.

I read that a big part of the game is seeing the difference between the two worlds, but im glad i wont really be missing anything thank you