Mario, Nintendo's long-running mascot, has used variations of 'Let's-a go!' as a cheerful send-off for decades, and the line became especially familiar with the 3D Mario games of the 1990s, when his voice was brought to life by Charles Martinet. As gameplay clips, speedruns and reaction videos spread online, the short phrase became a shorthand for starting something fun. It remains popular because it is instantly understood across languages and generations, needing no context to signal that an adventure is about to begin.