The trip and game will last for a week, and will span the country from corner to corner -- from the countryside to the jungle to the beach (though not all participants will necessarily get to see or explore every part). Each person selected to go on the adventure will also have to to comply with the rules, which among other things, may require you to be featured on Belize Tourism Board's social channels, wear branded Hide & Seek merch, and otherwise adhere to whatever itinerary your particular trip involves. Still, you'll be flown to stay, eat, and explore a wildly beautiful country with a tropical climate for free, so that's not a lot to ask.
To get in on the action, all you have to do is shoot an email to firstname.lastname@example.org with "Hider" or "Seeker" in the subject line by October 8, and explain why you should be chosen. They'll then randomly select five participants, and get them all prepped for their trips.
Unfortunately, there's nothing you can really do to give yourself a leg-up on the competition since the only qualifications are that you be at least 18 years-old, a U.S. resident, and available to travel between November 12 through 18. Though even if you don't end up on the receiving end of a gratis getaway, you could still presumably skip town to somewhere a bit warmer this fall for cheaper than you think.