It's a good game with some great platforming parts. The dream sequences are fantastic. Graphics and music are also great as you have already mentioned. It shows that the game had some decent production values.
My main problems with the game is that it has some pretty awful collision detection (especially in the later parts), the driving sections are just not fun for me, and the game gets fairly repetitive near the end.
It's a great game if you consider it as a pack-in (that's how I got it) but it's not something I would pay full price for. It's still the second best game in the J&D series, right after the original.