Never thought I'd update this, but whatever. If you're unfamiliar with how Undertale/Deltarune battle systems work, I'll give you the basics. You control a red heart on a 2-dimensional layout, and your goal is to avoid the objects heading towards your character by moving in any 4 directions. Some obstacles are different colours. They're pretty easy to understand once you see what they do: White objects do damage regardless of what you're doing. Blue objects only inflict damage when you're moving. Orange objects only inflict damage when you're not moving. Green objects heal the player.
Battle system and most of the attacks are inspired off of Undertale by Toby Fox.