Exergames offer an engaging approach to combat sedentary lifestyles and promote physical activity. While the benefits of multiplayer gaming are established, the nuanced effects of different cooperative modes remain underexplored for exergames. This study investigates the impact of cooperation (parallel work towards a shared goal) versus collaboration (joint effort towards a shared goal) on player experience in casual exergames. Results revealed that collaboration significantly improved both positive and negative affect, fostered stronger interpersonal connections, and was preferred by most players, while cooperation often was perceived as competitive and led to higher exertion levels. These findings illuminate the complex interplay between cooperation, competition, and collaboration in exergames.