The Gamification-Engine (gengine) is an open-source software project licensed under MIT that allows for the incorporation of various gamification elements into your product. Unlike traditional platforms, it does not come with pre-packaged graphics, layouts, or statistics, but rather serves as a framework for you to create a tailored solution, communicating with your application server via a REST API. The engine supports a variety of achievement structures including multi-level achievements, multi-goal achievements, single goals, and leaderboards that can be evaluated on a daily, weekly, monthly, or yearly basis, all while maintaining time zone independence. It also offers features that promote social interaction, such as competing for the highest score among friends, as well as geo-awareness, allowing users to see how they rank against others in their locality. Users can define custom rules in Python, utilizing variables such as the current level, as well as setting unique achievement properties and rewards that can be tailored to specific needs, including options for custom languages and translations. This flexibility makes the gengine a powerful tool for developers looking to enhance user engagement through gamification.