Besides the pure application of serious games as tools for knowledge transfer, a further trend has been observed in the last few years: The creation of games as an opportunity to gain practical experience and thereby also build up valuable knowledge. In this context several approaches are possible, such as using paper prototyping, game maker tools like Scratch, RPG-Maker, Construct 3 or Game Maker Studio 2, and the application of actual game engines like Unity. This contribution aims to discuss the possibility of creating games in a very specific, predefined genre using game maker tools that have been especially developed for use in an educational context and therefore offer didactic guidance. The Game Creator Tool which was developed as part of the Erasmus+ project Create Digital Games for Education (CDG4E) is presented in more depth. Using this tool, one can create decision card games inspired by the mobile game bestseller "Reigns". Within the project, the consortium created educational games in different areas such as fake news prevention and STEM education. In addition to these ready-made games, another focus was placed on using the tool itself as a teaching technique, for example to create games on a specific topic with school classes or within youth work, but also as an instrument for setting up dedicated "game jams". This contribution reports on the advantages and drawbacks of creating the tool itself by analysing qualitative and quantitative data gathered during the iterative design process of the Game Creator.