I did not try the game, as I wrote, I read the rules. I am not a solo ttrpg player. But I do have expericence in reading gaming rules, including ttrpg. Maybe you could tell by my nitpicking.
If you want to change things, there is only maybe the stuff about the unclear rules. Maybe it is a translation issue and the rules read clear as day in the original. I believe there was a translation error with the weapons as well. White weapons iirc and Fire weapons. That would be Bladed Weapons and Firearms, I suppose. (A Fire weapon would literally be a flame thrower)
And I tried to explain why it would not my cup of tea. Like with the killer behind the door. It kills the suspense (pun intended) if I am the creator and the player.
As a thematic advice, preventing your own death by going back in time in a horro scenario sounds cool. But that playing out as only a reroll sounds lame. A reroll is a known concept in tt. Calling it changing your destiny does not make it any better. And here comes the rule unclearness again. Maybe you meant that if you fail a second time, then you can do things differently. But it read more like, reality bends in a way that the need to do the roll ceases to exist.
The concept reminded me of the movie Happy Death Day, and I liked that one.