Why was I hit by the Pigeon update?

This year I experienced a rise in Tier 2-3 traffic which increased my AdSense earnings from about $400-500/month to $900-$1,100/month in one of my arcade games niche sites. But the traffic suffered a huge drop after Google introduced the Pigeon update back in July which was aimed at local results. As you can see in this graph a few days after the update (Red Line = Pigeon) the traffic dropped:

According to the report:

Pigeon:
Likelihood site was affected: 100%
Effect: -34%

I thought this update was aimed basically at local results for local businesses,etc but it seems that my site is no longer ranking good for people searching Google form other sites such as India.