Humble Bundle are giving away a 3rd game in their Halloween Bundle.
Technically it’s a exercise game aka, a fitness app called Zombies, Run! 5k Training.
The purpose of the app is to motivate users (players) to run a distance 5km, with an 8-week training program, which also includes an audio adventure for beginners. So it does have a story and missions, which are of course, exercises to keep you fit. There are over 25 workouts including walking, jogging, running and stretching.
You can even use ZombieLink to monitor your stats and view share your maps online. The app also supports exporting your stats to Runkeeper.
So head over to this page on Humble Bundle to get the game, and start running. You can still get The Spookening and Organ Trail: Directors Cut for free from the Humble Mo-Boo!-ile bundle which will run for 2 more days.