Just to come back to this thread, you may be right after all! I was watching Takeshi's Castle the other morning and I heard unmistakably the theme to Libble Rabble. It was used on the "stepping stone" challenge. It'd be difficult to find the actual episode where it was used but I can link to the song -
http://www.youtube.com/watch?v=n-YcSjy0zFk#t=0m19s
So yes, you may be vindicated. That's not to say the other songs are definitely from games but it does increase the likelihood substantially.