A fantastic story game that requires you to walk in real life. The Walk is more than just a (great) pedometer — it's a way to turn walking into a journey, a challenge, and a rip-roaring adventure. The first 4 episodes are free (about 4 hours worth of walking). If you have the ability, I encourage you to purchase the game to finish the story!
"A bomb explodes in Inverness station, and you're given a package that could save the world. To stay alive, you'll need to walk the length of the UK."