Simulated virtual realities offer a promising but currently underutilized source of data in studying cultural and demographic aspects of dynamic decision-making (DDM) in small groups. This study focuses on one simulated reality, a clock-driven business simulation game, which is used to teach operations management. The purpose of our study is to analyze the characteristics of the decision-making groups, such as cultural orientation, education, gender and group size, and their relationship to group performance in a real-time processed simulation game. Our study examines decision-making in small groups of two or three employees from a global manufacturing and service operations company. We aim at shedding new light on how such groups with diverse background profiles perform as decision-making units. Our results reveal that the profile of the decision-making group influences the outcome of decision-making, the final business result of the simulation game. In particular, the cultural and gender diversity, as well as group size seem to have intertwined effects on team performance.