This excellent zombie exercise game is now free to play

I haven't always loved running, but thanks to Zombies, Run, I can't stop.

It's part game and part fitness app; each time you run, you listen to a series of short radio plays that lay out a mission: You're on a supply run for medication, or trying to escape from a building full of zombies, as a radio operator at your base urges you to run, run now! Over time, you get to know the people at your base in Abel Township, and care about what happens to them as the story unfolds. You keep running because you want to know what happens next.

As of today, Zombies, Run is free-to-play on your iPhone—and soon, on both Android devices and the Apple Watch. It's a very accessible game, one that feels welcoming to both experienced runners and people venturing hesitantly back into the world of aerobic exercise. Its writer, Naomi Alderman, has written eloquently about her experiences with initially hating physical exercise, and then learning to love it on her own terms.

If you feel like adding a little more urgency to your run, you can turn on zombie chases, where you're told a zombie is hot on your heels, and you have to run faster to escape—something the app can actually track via GPS. There's a subgame within Zombies, Run as well, where the items you virtually collect by running your real-life routes are used to build your base by adding things like hospitals, farms, and fences to ward off zombie attacks.

The game won't be entirely free, of course; new players will get access to the first four episodes of the first season, and then ability to unlock one new episode each week. Otherwise, you can purchase more missions either season by season, or through an all-access monthly ($2.99) or yearly ($19.99) pass. Existing players get a discount, with an annual pass for only $7.99. Now get running, they're right behind you!