Bringing the gameplay of pokemon into the rhythm genre is a very unique concept indeed. The visuals here do remind me of the gbc pokemon games - my personal favourites - , with a few more colours of course. So, even though this uses the classic "falling arrows" rhythm gameplay, it does so with a fresh twist whilst still being accessible to fans of the rhythm genre.
While it is indeed a promising concept, there are a few issues that need to be addressed:
To begin with, while the falling arrows gameplay is very well known by rhythm gamers, what about the turn based battle side of things? I know that detailed tutorials are not really the priority in jam games, however knowledge of how the battles play out may be lacking. However, this is not such a bad issue as you simplified the UI enough that I believe any gamer could work this out fairly quickly.
As well as this, the music transitions are far too jarring - distracting, even. This threw me off the sense of rhythm a few times for sure. I'd suggest a fade out transition, or making songs that lead on from each other more naturally.
On the graphics side of things, the UI polish was a bit lacking. The most notable example of this is the health bars; instead of the health smoothly dropping down like in pokemon it just jolts to the new value. Sure, the gameplay is unaffected, but these little things are easier to notice when they aren't there.
Now for some thoughts on balancing. I ended up dying to the flower, as I was hit by its deadly poison attack, causing me to lose HP each turn. But, the damage was far too great. I was using the cure spell each turn, but whatever I had gained from that was immediately negated when I was reminded of the poison within me, slowly bringing me closer and closer to my demise. Eventually, I missed one too many notes, and was killed at the hands of a mere flower. How embarrassing...
I think that the damage scaling in this game is quite shocking - the golem and wizard hardly touched me at all, so I'd suggest a much smoother difficulty curve across the game as a whole.
With all that said, I'll go back to my original point - this is a very unique gameplay idea that I've never seen before. Well done on making the game!