I gotta admit, that was painful to watch. Consumables - except exp pills - rest upon resting/dieing/talking to kyubey. I need to find a way to make this clearer to the player. You spent a lot of time pressing Z for no reason :)
Equally, I should try to make the use of buffs/debuffs more clear. The first boss is easily defeatable at level 9, see this for example: https://mega.nz/file/qAhUhZDa#pKn4TyYnTBI8W4BBuLMG3BUgYNxVdx5igk8F1K7g5XY
But I guess that the use of debuffs will become clear anyway once they're coupled to damaging attacks. Your playing did show that the update to the 10 level cap was necessary. I had already had complaints of people getting filtered by that boss, but had no idea how that would be possible