Keeping your content fresh gives users a reason to come back. Use any in-app or game measurement tool to keep an eye on what users respond to. Use alpha-beta testing and staged rollouts to quickly test new features, in-app content, and game characters.
Updating regularly also gives you a chance to notify users about new content should users lapse. Notification, email, and social media are several channels to remind users to come back.
Check out the video below see how Kiwi uses frequent updates to engage and retain users.