Banjo Kazooie; nuts and bolts not working?

Awhile ago, a friend gave me the platinum edition of Banjo kazooie NaB. After finally getting an xbox and playing most of the game, i cant seem to be able to play the terrarium of terror level. Every time I attempt to enter a level. The jiggies will come up, and LOG will appear, but then it just continues to load and display hints. I have literally left it loading for over an hour and nothing happens. There are a few minor scratches on it. if anybody has a solution and any ways to clean game discs, id like it.