Gamboa is often remembered for his role as a pioneering educator and a meticulous craftsman. His style was characterized by a sophisticated use of abstraction and stylized figuration, often leaning into the "Neo-Realist" movement that sought to interpret the Filipino identity through a more geometric and intellectual lens. His compositions frequently featured balanced, rhythmic arrangements that emphasized the underlying architecture of his subjects, whether he was depicting the bustle of the city or the quietude of a domestic interior.

Beyond his personal portfolio, Gamboa’s legacy is deeply tied to his influence on the next generation of Filipino artists. By championing a more progressive and experimental approach to visual storytelling, he helped pave the way for the vibrant diversity of contemporary Philippine art. His works remain valued for their technical discipline and their role in the historical transition toward a modern, globalized Filipino aesthetic.