Patients with Acquired Brain Injuries or ABI experience various cognitive deficiencies that adversely impact their daily lives, as their ability to perform everyday activities, becomes severely limited. These patients would benefit more from engaging in unconventional cognitive rehabilitation, specifically rehabilitation using Serious Games. However, it is difficult to categorize cognitive disabilities due to their heterogeneity; therefore individualized rehabilitation interventions are required. It is also challenging to design games for cognitive rehabilitation, as the complexity and production cost for these games are usually very high. There is an abundance of recent studies on cognitive rehabilitation, particularly game-based interventions. However, some studies explain how to design games that are enjoyable and usable for patients with cognitive disabilities. Hence, this study addresses this issue with a proposed framework for therapeutic game developers targeting patients with cognitive deficiencies. To this end, a prototype Rehabilitation Gaming System (RGS) was developed and evaluated by therapists. A 7-point Likert scale usability questionnaire was used and the mean scores for layout/design (5.94), ease of use (5.40), easy to learn (5.76), usefulness (5.96) and satisfaction (6.1) indicate that RGS has good usability. Therapists are willing to use RGS for rehabilitation purposes. Practitioners, game developers, and patients in the healthcare field will be able to use the proposed framework as a guide and tool for designing and implementing games targeted for cognitive rehabilitation.