How many movies have Betty Chan Kwai-Wa and Phillip Ko Fai collaborated on?

They have worked on 12 movies together! Their first movie together was Mission Thunderbolt (1983) while their highest rated movie together was American Commando 2 — Hunting Express (1988). They have not worked together since American Commando 2 — Hunting Express (1988). They are most known for their action films together.