It's a great game, I'm not sure if it's challenging because I just beat the bosses just fine but maybe it's pretty challenging for others not to mention there's many bosses too to beat too!
I think it's cool that you can counter the enemies attack back at them but I had a problem with checking the attack cooldown, I know I can check it based on the spin but I absolutely can't tell the exact number of my attack and that's the problem as that's the only mean of defense as well, I mean if knew the exact number I would have do all out attack while keeping the last attack as an insurance in a pinch.
I play safe by only doing attack once in a while as there's no dash, roll, or whatever, only that shackles attack and spin, I don't really use spin at all since it tend to miss/didn't hit the projectile not to mention the aim is also off too and consuming spin energy as well.
*Just a suggestion, maybe you can put an indicator which inform player about how much attack they had left or maybe you like to keep it vague and let the players to guess or keep track themselves? that's fine too I guess...
*Another opinion of mine, maybe you could put a detail on the arts, I also put faceless character on my game thumbnail but I properly give them face on the actual game or maybe you can put a shadow to cover her eyes if you want to make her anonymous type.
This one is just probably me, idk if it's a bug or there's really only one boss battle bgm in the game, anyway I'll just be honest that I was yawning after hearing the boss bgm over and over.
*I'm pretty sure it would be a great idea for each stages to have their own bgm or even better for each bosses has their own bgm.
Oh yeah, I wish I could take a year long break too...
That's all I guess, if I write something wrong or missed something, let me know.