I'm not saying the game is bad, the opposite in fact. I just don't find it fun. (also no worries I gave you a rating that reflects that.)
It has many things going for it. It looks amazing and obviously you did a lot of polishing.
My problem is not that the game is too difficult. I love difficult games. My problem is that if feels cheap to get sent back so far for every little mistake. (some of them not even being my own fault btw. I had multiple instances where the character would just flat out refuse to execute moves I input or get stuck on level geometry.)
I also found out about the strategy how to defeat the bull enemies myself when I was playing it. My problem isn't that its difficult, its not intuitive and it feels like I'm fighting the game design instead of the enemies. There are a million ways to make 2d sword combat difficult. Look at hollow knight, look at salt and sanctuary, look at castlevania.
You could, for example, have the enemies send out a shock wave when they smash the ground, forcing you jump over it. You could also make them move forward a lot when attacking, or just increase the size of the attack itself.
About the collision thing there is certainly an argument for both sides and if you disagree that's fair. I just found it a bit unresponsive to slide of edges.
But about the double jump I just plain disagree with you here. I can't think of any game where the height of the double jump depends on the timing. Metroid only allows you to double jump in a certain window of time but that is completely different. (I would like to know what other games you are talking about here btw).
Obviously this is just my take and you know the game a lot better than me. So make of that what you will.
Please don't take this as a personal attack by the way. I critiqued the game so harshly because it really has the potential to be amazing.If you can fix all of these things I would gladly buy this for it's normal price and recommend it to some of my friends who would enjoy a game like this.