Cognitive tasks usually used in rehabilitation or evaluation of cognitive functions are viewed as effortful or frustrating, which often leads to participant disengagement and high mental workload (MWL). The challenge is to increase the task’s commitment while decreasing MWL and maintaining similar impact on cognitive functions. Introducing playfulness could decrease the part of MWL due to endogenous factors (like demotivation) without affecting the task’s cognitive aspect. Nevertheless, there is no study investigating the link between ludification, commitment, and MWL and the performance’s repercussions. Therefore, we developed a protocol to compare the subjective MWL for three conditions of a cognitive task that differed depending on the degree of ludification. Overall, our results showed that performances were not influenced by ludification, confirming that it did not reduce the effects on cognitive functions solicited during the task. Regarding the impact on engagement and MWL, it will be discussed in light of different models of MWL.