I came up with this story idea based off of the "Cicada 3301" puzzle on the Internet.
You play as a person who comes across a similar puzzle on the Internet, and you sign up and set out to solve it. This puzzle, however, will involve more going outside and doing things in the real world than just solving puzzles on a computer. Because the world is a big place and the makers of the puzzle can't set up a game for everyone, you and only a few other people are accepted to be able to participate in solving the puzzle. This makes your goal to complete it before anyone else does and win, but some challenges will require teamwork to pass... The storyline will change depending on how you solve puzzles and get answers.
I'm not a big fan of writing stories, so if you really like this idea and want to make a story game out of it, feel free to do so. I'm probably not going to make this storygame.