This qualitative pilot study provides an example of how generative Artificial Intelligences (GenAI) can be applied in an engineering course focused on the development of playful educational technology. In this context, playful educational technology refers to games or game-like applications designed for educational purposes. We explore various applications of GenAI in creative design processes such as brainstorming, acting as a collaborative partner in design, facilitating image and sound creation, and aiding in the resolution of coding challenges. By examining examples from 36 engineering students' semester-long projects, we highlight the potential and drawbacks of GenAI as an extra teammate in enhancing the design process for developing educational game-based learning experiences. Key findings from the study include: The students opted to use a GenAI as a teammate, whose input required validation. They employed GenAI in areas where they found it effective and where no major ethical issues were involved. It was also surprising to observe the wide variety of AI tools the students incorporated.