This game has a new layout to previous Lego games. Rather that the small hub with the all levels contained within in it, this game gives you six "hub worlds" One each for the first three films and three for Crystal Skull. These hub worlds are where you collect your extras or red bricks. For those who have played Lego Harry Potter, these hubs are similar to the Hogwarts hub in that game. I for one rather like this new layout.
The story levels for the first three films are new levels, not copies or re-hashes of the levels from the first Lego Indiana Jones, so it is a seperate game.
Also, for those of you who care, it is also a fairly easy 1000G on Xbox 360, with about 675G coming from just playing the game towards 100% (excluding 100% achievement)