A game within a game, at least sort of. You and your brother participate in the game made to celebrate the 5th anniversary of the village you two are currently living in (Since it was created).
The game is called 'Seek, Hide and Seek Again' because of the game's cycle: Look for a hidden flag, Hide from other players, and seek the other players' flags or flags that are yet to be found.
And the game ends when all hidden flags are found. The one with the most flags at the end wins. But of course everyone still gets a prize, only, the more flags you have, the better your prize is. Sort of like an Easter Egg Hunt. With the addition of being able to steal eggs from the other players. When you reach the game site, the full game instructions are announced.
But it seems they kept a part of the game a secret until the end... and you find your brother and yourself in a bad situation.
If one of you ends up with the most flags, at least.
-Takes place in the future, with advanced technology.