**6. Conclusions**

The experiments provide encouraging results, and we confirmed our belief that playtesting with agents is important and worthy of further research. Playtesting agents can play in the same scenario repeatedly and with good results, while repetitive play (e.g., playing the same scenario fifty or more times) is probably tiresome for human players, who are therefore more prone to making errors. We also confirmed that our novel metric performed as expected, because the metric scores revealed a certain consistency when traversing from basic to state-of-the art playtesting agents. To the knowledge of the authors, such a metric (i.e., one that would evaluate playtesting game agents based on their game feature performance) does not ye<sup>t</sup> exist. The creation of it is necessary to establish common ground for the research conducted in the domain of game features and in the domain of playtesting agents.

Through a series of experiments, we were also interested in how di fferent evolutionary-based playtesting agents explored the search space. The valuable information obtained in our experiments will serve us as a steppingstone in the development of new playtesting agents that are based on modern Evolutionary Algorithms, as well as Swarm Intelligence algorithms.

**Author Contributions:** Conceptualization, D.N., D.V. and I.F.J.; methodology, D.N. and I.F.J.; software, D.N. and J.D.; validation, D.N., I.F.J. and D.V.; formal analysis, D.N. and I.F.J.; investigation, D.N.; resources, D.N., I.F.J. and J.D.; data curation, J.D.; writing—original draft preparation, D.N. and I.F.J.; writing—review and editing, D.N., I.F.J. and J.D.; visualization, J.D.; supervision, I.F.J.; project administration, J.D. and D.V. All authors have read and agreed to the published version of the manuscript.

**Funding:** The authors acknowledge the financial support from the Slovenian Research Agency (Research Core Funding No. P2-0057).

**Conflicts of Interest:** The authors declare no conflict of interest.
