Aim: study aimed to examine the acute effect of a battle mobile game playing between 3 games (45-60 min) and 7 games (135-180 min) on heart rate (HR), stress levels, cognitive function, and visual short-term memory (VSM) in healthy university students. Methods and Results:Twenty university students aged 20-22 volunteered. The Realm of Valor (ROV) mobile game was used. Participants were separated into 4 teams, and each team was randomly assigned to play either 3 games or 7 games. All variables were assessed before and after gaming. Results showed that HR increased in both gaming conditions after playing (p<0.05). Stress levels were higher after 7 games than after 3 games (p<0.05). Cognitive function was greater changes in the 3 games than that in the 7 games (p<0.05). Neither the 3 games nor the 7 games affected visual short-term memory. Conclusions:Playing the ROV mobile game for 7 games or more than 135 minutes could increase stress levels, whereas 3 games may not affect stress response and cognitive function. Thus, suitable time spent playing games, especially a battle game, should be advised to avoid inducing stress responses in university students.