Thank you! The download list provides a walkthough, but it's for collecting endings. For the main storyline, I've basically set it up to require multiple plays and throws, following a relatively linear path, so I haven't prepared a corresponding guide. I think the B line is still relatively simple?
However, at Andershcha part, you need to have cleared a certain ending once, then choose to use the ability to dig him, and finally select "Nessie!" in the time-limited options. This is what I think is the unique and potentially confusing part of this chapter.
If this doesn't solve your problem, please describe again exactly where you're stuck!