"In Horizon, the world is your lobster," says the American woman - or avatar of an American woman - who narrates the clip.
"It's about getting out there and trying new things. Making a mark. Making friends with an Australian named Mark".
"Actually, I'm from New Zealand. Heh," replies Mark, with straight-from-central-casting lazy vowels.
In Horizon Worlds, which requires a VR (virtual reality) headset from Facebook-owned Oculus, you can socialise, or collaborate with others to build worlds.
The cheesy dad jokes suit the cartoony look of Horizon Worlds, Version 1.0.
But Facebook founder Mark Zuckerberg has big plans for this new digital frontier (or not so new, for those who remember Worlds Chat in the 1990s, and many imitators since).
After signing up almost two-thirds of the world's internet users to apps including Instagram and WhatsApp, Facebook founder Mark Zuckerberg told investors that his latest obsession was building a "metaverse" — a nebulous and much-hyped concept denoting an immersive virtual world filled with avatars.
"In the coming years, I expect people will transition from seeing us primarily as a social media company to seeing us as a metaverse company," Zuckerberg told analysts.
The company has said it is spending billions of dollars a year on virtual and augmented reality more broadly, in a bold bet on a futuristic digital world as the race heats up to build the next computing platform beyond the smartphone.
Facebook now has more than 10,000 staff working on various projects in the space, including the development of AR (augmented reality) glasses to overlay objects and information on to the real world, and a wristband that will allow wearers to interact with that world through subtle finger movements.