Really creative an interesting game !!! This got to be one of the best submission I tested so far. here is my feedback:
-Really Good sense of humor
-I really like the variation in the attacks.
-I think it would have been a better touch to make something else instead of the burger exploding after winning 😅.
-I'd also recommend increasing the quality of the sprites and the background image at the start of the game (it wouldn't make any difference but it would give the player a good first impression about the game)
-I really encourage you to re-use these systems you implemented into making a full project of an Undertale fan game, you really did a good job at mimicking the systems in Undertale .
Looking forward for further updates !!