Nowadays, video games are all around us, and predictions suggest they will become even more widespread in the future. For this reason, it is crucial to investigate the possible positive and negative consequences of playing video games. The most popular genre of video games is action, which is also the most interesting for cognitive psychology research, since playing requires many perceptual and cognitive abilities. Research into how gaming can influence or relate to cognition is on the rise; however, this topic has not yet received much attention in Slovenia. Our research examines the connection between playing action video games and the ability to mentally rotate objects, track multiple objects, and switch between tasks. On a sample of adults (18–37 years old) we compared non-gamers (N = 81) and action video game players (N = 82). The results show that playing action video games is an important predictor of mental rotation ability and faster reaction times in task switching. Even though action video game players switched between tasks more quickly than nongamers in all conditions, the groups did not differ in the switching cost, which is a major indicator of cognitive flexibility. The effect on attention span was not so clear; statistically significant differences between action gamers and non-gamers were noticeable after excluding one participant who deviated from the mean of their group by more than 3 SD. The results indicate that playing action video games can have positive effects on certain cognitive functions, but require further cross-sectional and experimental studies to provide more information on the causes and mechanisms of cognitive enhancement.