I never played Obi Wan, but saw screenshots in video games magazines (and read reviews) as well as various videos of the game. In many ways it reminds me of The Phantom Menace video game.
Two things seemed to be interesting in OB - first, it shows more of the time, when episode I takes place. The other one is that the levels such as Coruscant showed quite a lot of NPCs. I can speculate further, that it is also one of the first games, that shows Coruscant in a more or less presentable way. I know, that TPM had a level with this planet too, but it was too simple. Shadows of the Empire shows only a few locations, that weren't too impressive from a point of view of city infrastructure and its dwellers. =)