When Lego Indiana Jones came out I was the first in line. I fell in love with Lego Star Wars and sometimes restart a campaign to this day. Both these games are great, but Lego Harry Potter falls short.
It does have the destroy everything way about it, but when there is too much to destroy it can get a little irritating. Plus I don't know how many times I had to look online to find my way around Hogwarts after completion of the story. I think Lego Harry Potter lacks the sweet simplicity of the other Lego games.
I would like to say one very important thing about this game. They started a new trend of certain item/blocks that you can place anywhere you like within the expected area. The idea is to give the player more freedom over the surroundings, but more often it just provided more frustration for me. There seemed to be no room for margin of error and I could never seem to be able to restart after I messed up placement of the items (which I did a lot).
I know this may sound like an amateur gamer complaint, but I like being told what I need to do. Sometimes the game just had this roundabout way of completing a scene that I either didn't know what to do or I accidentally finished a spot before I wanted to. This has always been kind of true for Lego games, but with Harry Potter it seemed worse than ever.
The spells are kind of neat, but when you are in free play mode it is difficult to switch between them since the button to switch spells quickly and the button to switch characters are the same button. Plus, I felt that since every level had some kind of object that needed an "evil" character, one should have been available sooner.
One last item, when picking characters from the ones you have bought, they oscillate between silhouette and the actual picture. That was an unnecessary affectation that proved more frustrating since (even if you have bought the character) you can't pick it if the picture has fluxed to the silhouette. That just seems stupid to me.