Wind-Up Knight sees 100,000 downloads in 24 hours after going free

The iOS version of California-based Robot Invader’s side-scrolling platformer Wind-Up Knight is seeing more than 10,000 downloads an hour after switching to a free-to-play model.

Robot Invader originally released the iOS version of Wind Up Knight on Dec. 15 as a $0.99 paid title, but made the game to a free-to-play on Feb. 21. According to Robot Invader’s co-founder and former Android developer advocate Chris Pruett, Wind-Up Knight typically had a few hundred downloads a day before going free, but by the beginning of the month the app had dropped off the radar.

The effect of going free-to-play was immediate — yesterday Pruett tweeted the game had seen 20,000 downloads within 12 hours of the change and at 9:00 am this morning Pruett followed up, stating the game is now seeing more than 10,000 downloads an hour. According to Pruett the game has added approximately 100,000 new users in the last 24 hours.

The game is also currently being featured as the free app of the day on the popular promotion site Freeappaday.com, but so far Pruett isn’t sure how much influence the feature is having.

“It’s pretty impossible to separate the Free App A Day influence from the general buzz about the app going free (there are many aggregators that noticed the price drop and reported it anyway), but regardless we are very happy with the result,” he explains.  “I think it is likely that Free App A Day brought a huge number of users today, and the real test will be to see how long we can sustain a position in the top charts once that promotion ends.” Pruett used to work as a senior developer advocate for games on Google before heading off to do his own venture.

If the popularity of the game keeps pace, Wind-Up Knight may be the latest free-to-play indie game to find big success on iOS. NimbleBit’s hit games Tiny Tower and Pocket Frogs have each racked up more than 10 million downloads and Imangi Studios’ Temple Run has seen more than 36 million downloads. U.K.-based developer Hogrocket has also weighed in on the strength of the free-to-play model, saying their next game will be likely be free, even though their game Tiny Invaders has been successful using the paid model.

Readers may remember the free-to-play Android version of Wind-Up Knight made our Nov. 11 roundup of the top free Android apps in the No. 39 spot shortly after its release.