The theme tune is composed by the award winning Hans Zimmer. Hans went on to have a hugely successful career in Hollywood, composing for such films as Rain Man, Dark Knight, Inception and the Pirates of the Caribbean series.
I remember being about 3 Years old at the time when this came out. It was always in the lunchtime slot after "Neighbours". The theme song for G4G sounded like something performed by It Bites. From what I remember, Henry Kelly was quite a joker. I just hope Challenge TV pick this show up one day...