I liked Undertale decently enough but it's for sure flawed. Half-baked combat, weird difficulty curve, minimal story (with high highs but a lot of lows in between), humor that misses more than it hits.
Deltarune solves basically all these problems immediately so I'm really looking forward to the rest of that game.
"You're childish. What are you getting? Are you getting strawberry? Ha! That's such a childish flavor, only children eat strawberry."