They did a good job with the gradual changes, but I couldn’t watch it all the way through. The main cast is just too irritating to watch. If I wanted to watch (the equivalent of) children deal with an interesting premise in adult bodies, I would just go back to Big or 13 Going On 30.
Your idea of it is a hilarious (sort of) possible backstory to all of the thriller/horror movies where one person is ‘the only one who remembers X!’