You're in luck, next session starts August 15 ;)
I think gamification is sort of a way to change your users frame of mind while they engage with your product. Kahneman doesn't really talk about games, but he does talk about ways of influencing behavior by affecting a person's state of mind.
I listed "The Power of Habit" first because I have a feeling that games have more to do with rewards and cravings than they do with judgement and decision making (more the topic of Thinking Fast and Slow). But both books relate to how we can steer decision making.
* Aside: I googled "priming anchoring" and got a result about UI design also mentioning loss aversion, another topic from Kahneman's book. http://www.uxmatters.com/mt/archives/2011/03/how-anchoring-o...
Fun fact: your users will hate losing badges even more than they like earning them. :)
I have emailed the author a few times, he has been very helpful.