There are apparently many unusual easter eggs contained in the Technos Double Dragon video games (1987+). I thought a piece of music heard in Mission 2 (& in the opening mission of the NES / Famicom version) of Double Dragon II: The Revenge ('88) may sound like the theme music to the Peanuts (Charles M. Schulz) animation.
Other clues to support this theory in the Double Dragon games: Note the collections of construction materials in the background of some of the stages. Steel beams in Mission 2 (commonly used in modern buildings). Double Dragon II: The Revenge in 1988, has more of these raw materials, including bricks & cut logs. The groups of wood made me think "WOODSTOCK", the name of a Peanuts character (Snoopy's Best Friend).
Marvel Comics (known for superhero Spider-Man) may point the way to some other links. They published Double Dragon as a 6 issue mini series in 1991. There was a crossover Spider-Man / Peanuts comic strip (a collaboration by Schulz, John Romita Sr. & fan Mike Burkey). This was published in The Romita Legacy in 2010. One thing that takes place in the story? With some assistance: Charlie Brown actually kicks the football after Lucy props it up!
