I set up an IntelliJ project with the demo games several weeks ago and I have spent some time kicking the tires. It feels comfortable because it is GWT based, which I have used a lot.

I was in the game business (dev for Nintendo and Disney) for 2 years, but that was about 15 years ago. Currently, my granddaughter wants us to write a game together, so I have been looking for a platform to do that.

There are a lot of cross platform options, including straight up HTML5, so I wouldn't bet that PlayN gets a lot of traction.