The current naming system in place for our apps does not allow users to reset their nickname. This is due to it being a simple system that is not tied to any login like what Apple has.

If you use the Google+ feature, where you see your leaderboard and achievements, you can sign into the system with your username and password, it may backfill with your nickname if it was used in conjunction with Google+.

As an alternative, you may be able to keep your nickname if you still have your old device and access to the application. You can change the nickname in the game on the old device. The naming system will then release the nickname for you to register it on your new device.