Fun, for a hidden object game though I would have liked more of the mini puzzles. The background story, diary entries, probably take far too long for most people to sit through. They can be skipped entirely but it would be cool if the player could control the speed.
Many object are hidden behind others, some goals cannot be finished before another specific goal is finished, and some objects cannot be looked inside of until a specific goal is activated. Definitely follow the hidden objects golden rule- at some point, just click every single square inch, twice.
Latull17 about The Mystery of the Crystal Portal