Deltarune - Flashbacks, or alternate dimensions

Frisk… Suzy…
Kris… Susie!
DON'T! STOP!
[The entire universe becomes white]
GREAT JOB! I hope ya all happy! YOU JUST NUKED REALITY! The universe now looks like mosaic piece! I swear to god, this is the reason why friends are dangerous!

We. Need. More. Young. Susie. She's so goddamn adorable.

This has also given me a thought… What if Deltarune pulls a Bioshock Infinite and they end up in Undertale? Maybe even meet up with Suzy or something.