Fontana was a one-hit wonder, but his guitar player was Eric Stewart, who was part of 10cc in the 70s, and then went on to play with Paul McCartney for many years. Eric's lead guitar riff at the start of Game Of Love is epic.
BTW Game of Love was written by Cliff Ballard, whose other notable hit was "You're No Good" for Linda Ronstadt. I think they're both in the same key.