Stroke affects the population worldwide, with a prevalence of 0.58% worldwide. One of the possible consequences is the negative impact in the motor function of the patient, limiting their quality of life. For these reason, Brain-Computer Interfaces are studied as a tool for improving rehabilitation processes. Nevertheless, to the best of our knowledge, there are no Brain-Computer Interface systems which use video-games for upper limb motor rehabilitation. This study aimed to design and assess a Human-Computer Interface that includes electroencephalography, forearm motion and postural analysis, with healthy subjects. This assessment was made by designing two scenarios in which the participant carried out exercises involving the mouth and the hand and forearm trajectory symmetry. Results show that the system is ready to be tested on patients, since the participants were comfortable using it. Also, the quantitative results, particularly, the metrics used in the video-game, are an important start for health professionals to characterize motor rehabilitation in stroke patients, enabling the path to the use of the designed system in motor rehabilitation therapies.