The training of motor skills is a crucial aspect of medical education today. Serious games and haptic virtual simulations have been used in the training of surgical procedures. Otherwise, however, a combination of serious games and motor skills training is rarely used in medical education. This article presents Skills-O-Mat, an interactive serious game for training rhythmic and period motor skills. In its first application the game supports dental students being trained in alginate mixing in a blended learning course. Designed as reusable component, the game follows an effective learning design and uses constant immediate feedback to support students' learning. The effectiveness of the use of the game in learning was compared to learning in a traditional workshop using a randomized controlled trial (N = 30 test group, N = 25 control group). Participants of the evaluation were dental students aged 20 to 23 years in the 2nd year of study (40% male, 60% female; 46.7% with no experience, 50% had little experience in mixing alginate). An analysis of the results of the evaluation gives indications of the positive learning effect of the game. The game was rated a valuable instrument for teaching and developing practical skills.