If you are just starting "Part 1," you'll notice a few unique mechanics that set it apart from standard RPGs:

The story kicks off with a massive "what if" scenario involving the protagonist Otsuu resetting the timeline to save a friend, which causes a butterfly effect that ruins the lives of other characters.

Mary Skelter 2 (NS) Gameplay Walkthrough Part 1 [1080p 60fps] Red Venom Corp. YouTube• Nov 5, 2019 Are you having any trouble extracting the .rar files, or Mary Skelter 2 - Steam Community

The most interesting thing about Mary Skelter 2 is its identity. While it is titled as a sequel, it actually takes place in an where the events of the first game ( Mary Skelter: Nightmares ) are completely rewritten.