There is a secret mini game hidden within The King of Fighters: Battle de Paradise for the Neogeo Pocket Color. When inserted into a non-Color handheld, Yosaku Game becomes playable, which is actually a sequel to a forgotten SNK arcade game from 1979… which happens to be based on a popular song at the time… about a lumberjack chopping down trees. Yeah, this is a pretty crazy story.
See it here: