Collecting the blue pages and not the red?

You might find that this game gets a bit difficult and the puzzles ramp up as you go farther along. I did finish the game when I was a kid, but my dad had gotten a walkthrough (that was physical, included a map, and was written from the perspective of a fictional person in the world documenting what they did to get through the game)

The maze and the music tone-matching with the organ were especially difficult if I recall.

Also there are actual novels to go with the world that my dad had too. I never played the other games but the books were okay. They cover the back story of how in the heck do books transport you anyway.