As the complexity of video games continues to evolve, so does the importance of effective game-testing methodologies. To this end, automated game testing has emerged as a pivotal approach to ensure the quality and functionality of modern games. This paper presents a comprehensive survey of metrics utilized in automated game testing, aiming to provide a deeper understanding of the parameters used to evaluate the robustness and performance of video game testing activities. Through the conduction of a Systematic Literature Review and the Open and Axial coding approaches, the results of the study provide a taxonomy of 26 different metrics for video game testing assessment, grouped in six higher-level categories. The elicited set of metrics can serve as a tool for game testers, researchers and tool developers to evaluate testing approaches and techniques and enable comparability of research results.