The NES game The Flintstones: The Surprise at Dinosaur Peak! contains a Debug Menu, that’s already known about. http://www.gamefaqs.com/nes/587284-the-flintstones-the-surprise-at-dinosaur-peak/cheats
With it you can enable invulnerability, listen to sound effects and choose a starting stage.
In the hex editor, there is also a potential menu called Test Mode: