That could be amazing with the right people.
If I were to DM such a game, I'd tell my players to prepare characters for a pirate themed game, and no magic users, although there will be magic elements in the game. I'd start off the game like normal, letting them meet in a bar in some harbor town. Then they overhear two sailors arguing: "you are ridiculous, there is no way that treasure really exists!"
And once my players ask them about this treasure, the sailor responds indignantly, "the greatest treasure of all time. Are you dense?"
If they asked for more information, the sailor would explain, "once there was a great pirate, the king of pirates. He had fame, power and wealth beyond your wildest dreams.
Before they hung him from the gallows, these were the final words he said, 'My fortune yours for the taking, but you'll have to find it first. I left everything I own in One Piece!'
Ever since, pirates from all over the world set set sail for the grand line searching for One Piece, the tresure that will make their dreams come true."
And then, I would hit play on my laptop.http://youtu.be/TAXaRZ831F8?t=19s