Small-sized software enterprises have tried for years to make major changes to improve the software development process and, consequently, the quality of their products. Many small companies are focusing their efforts on conducting software process improvement initiatives to mature their software processes and to deliver products on time and on budget. Nevertheless, these initiatives are not always successful because human factors are still difficult to control leading to a high failure rate due to a lack of involvement and motivation. Gamification can be used to motivate staff and increase participation and commitment to improve the chances of success when a software process improvement initiative is conducted in these companies. In this study, a gamification strategy was designed to add game-like elements into the GamiSPI tool for supporting software process improvement activities. Significant research has been carried out, but our approach aims to apply gamification in a distributed way by enabling employees from different enterprises to share information and knowledge, combine efforts, support communication, and collaborate with others towards common improvement goals. The effects of gamification were assessed using quantitative and qualitative methods to show that this strategy can increase the involvement, motivation, and ambition of the participating staff.