These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
YMMV: Rainbow Magic
Awesome Art: Return To Rainspell Island was a co-production with a Japanese studio, and it shows.
Some of the books, such as Elisa the Royal Adventure Fairy's, have very detailed art.
Awesome Music: The music for the "Create a Fairy" game on the website.
First Installment Wins: The first series is considered the best, to the point that Return to Rainspell Island is a direct sequel to it and ignores almost everything that came after it.
Fridge Horror: Jack Frost's threats to lock Rachel and Kirsty in his dungeon for 100 years can become this when you remember that Time Stands Still in Fairyland. They'd return to the human world at exactly the same point as when they left...but they'd have lived through 100 years of imprisonment. And that isn't factoring in whether they'd age in Fairyland...