Developer-friendly professional authoring tools have greatly simplified entertainment videogame development. However, this simplification had a limited impact on serious games, which require the active collaboration of developers with educators and other stakeholders. To address this issue, we present uAdventure, an easy-to-use game development environment for narrative "point-and-click" graphic adventure games. uAdventure started as a re-implementation of the previously validated eAdventure authoring tool, now built on top of the Unity game platform. The idea is to enjoy the advantages of the Unity professional environment while reducing its complexity to allow non-developers to author serious games. uAdventure is designed to simplify the creation of serious games that include educational-oriented capabilities such as learning analytics without requiring programming knowledge and has been formatively tested with different types of users and in different settings. Initial testing was carried out with a group of heterogeneous users with different computer usage profiles in a vocational environment. In the second round of testing, it was used by students of two different university courses to develop serious games that include educational features such as location-based mechanics and learning analytics. The results of these formative evaluations show that uAdventure can be used as a serious game teaching tool and that it simplifies the creation of serious games with educational features by non-expert authors.