Motivational effects during a simulated educational game should be studied because a general concern of lecturers is motivating students and increasing their knowledge. Given advances in internet technology, traditional short in-class games are being substituted with long web-based games. To maximize the benefits of web-based simulation games, a game should instill intrinsic motivation in students and encourage them to adopt deep-learning strategies. We have conducted a quasi-experimental study of 53 students, divided into game and no-game groups, as part of an operations management course. During the course, the game group played a web-based simulation game lasting 7 days; the no-game group did not play this game at all. The findings revealed that students who played the game experienced a deeper level of learning. However, students who did not play the game felt more competent and exerted greater efforts. These results are useful for challenging the assumed benefits of educational games at motivating students. Furthermore, our findings open up opportunities for finding more factors that affect the motivation and behavior of individual students.