Got 100% a few days ago. It was great fun, and I agree that it was better than Batman and Indy (especially Indy 2).
The difference in the games is atmosphere. I enjoy the HP movies, so hearing the music and using the familiar characters was a plus for me.
If anyone needs help, let me know!
Here are a few tips that get asked about the most about this game:
The items that have red sparkles are used by evil characters, and the first chance to get one is in Year 4, Chapter 1.
Professor Flitwicks classroom has two entrances (on either side of the face on the wall). They are different, so go in both to get full completion!
The snakes that pop out of baskets are usually used to scare a character, you just have to find a way to get a character next to it.
Using codes/red brick cheats do not affect achievements, there are a few you HAVE to use them to get.