Elicited physiological affect in humans collaborating with their robot partners was investigated to determine its influence on decision-making performance in serious games. A turn-taking version of the Tower of Hanoi game was used, where physiological arousal and valence underlying such human-robot proximate collaboration were investigated. A comparable decision performance in the serious game was found between human and non-humanoid robot arm collaborator conditions, while higher physiological affect was found in humans collaborating with such robot collaborators. It is suggested that serious games which are carefully designed to take into consideration the elicited physiological arousal might witness a better decision-making performance and more positive valence using non-humanoid robot partners instead of human ones. © 2019 The Authors