I do agree! I also loved the visuals, and thought it could use some smaller random encounters.
The game feels a lot like undertale, but that isn't necessarily a bad thing, as it was a pretty great game. I personally don't mid the barren background too much, and was used to more strict reflex timing, and although the combat got more and more difficult(I struggled a bit with the bar fight), it wasn't that big of a problem(think of cuphead).
However, the fights were all fairly long, and I wouldn't mind them being just slightly shorter. It would make learning the patterns easier and less frustrating when you die. I am also curious to see how the diffiiculty scales up, as there isn't much you can do before it becomes a complete clutterfest. You could try to change it up a bit with various challenges, without completely abandoning the core mechanic. For example, I noticed how you clear levels without jumping at all, so you could have a ceiling tht slowly goes down and prevents you from jumping. Or, you can have a battlefield that slowly narrows down, from 5 lanes to 2 lanes. I will once again be referencing Undertale for this. In undertale, you coud have a normal heart, a ddr heart, a blue heart, a yellow heart, and so on (I haven't played all of Undertale yet so I may not know everything). This helps the game stay varied and interesting to the player (See this https://www.youtube.com/watch?v=hbzGO_Qonu0)
Some stray thoughts:
The visuals are in my opinion, absolutely amazing, with a rare aesthetic.
The music puzzle was, whilst easy, very fun.
Overall:
Lots of potential with a bit of variation, interesting gameplay, 4.5 out of 5