Hey VikfFro, good to see you here and thanks for playing/reviewing.
I'm glad the slow grind came through as intended, as does the long tutorial.
We did plan to have fights displayed on the calendar, and there were originally 4 planned (1 each week), which would unlock on completion respectively. (There was also a countdown made, but was not implemented due to rushing for the deadline.)
The text did have a variable which allowed for varying speeds, etc. but we did not utilize them due to being rushed for deadline.
The game ends at the first fight, so you've experienced all of the story (for now).
In regards to the boss fight being too difficult; originally the fight was playtested with placeholder art, and the positioning/wind-ups made the fight much easier to parse. However upon rushing to implement as much final art as possible before the deadline, we did not have time to properly playtest the fight, and so it may be difficult to read which direction to dodge, etc.
The fights were also playtested with a slower BPM track, and were only updated to a faster BPM before submission; which in hindsight was a mistake on my part to do, because I had only playtested according to an easier fight.
Apologies if it was needlessly difficult because of this.
The On Beat detection is definitely something we'll look into, and it went through many revisions throughout the process of making the prototype.
(I think one of the bigger issues with keeping time currently is the lack of visual/audio feedback that lets you know if you are on beat correctly/incorrectly. Originally the Player's and Opponents Hearts were meant to beat in time with the track, acting a visual metronomes for the Player. This is mildly implemented, but not properly, and thus becomes confusing rather than helpful.)
The game will be updated post-jam review phase, so keep a look out for the updated version/s.