Twin Dragons is yet another recycled Jackie Chan film. By that, I mean the movie was originally released in 1992 in Hong Kong but has been re-released in the U.S. given Chan's rise in popularity with Rush Hour, but I might as well be talking about the plot.
Twin Dragons falls short of a good Chan film on many respects. The two foremost reasons this movie doesn't cut it is because there is no final spectacular action sequence near the end of the movie, and the segment of failed stunt out takes that typically appears after the film has ended is not present. These two characteristics alone make many Chan films worth watching. Given their absence, Chan has to rely on his charisma and the general plot and pacing of the story to keep the audience interested. On the former count, Chan succeeds---doubly so. With regards to the latter, the plot is unsurprisingly underwhelming. (No one I know watches a Jackie Chan movie for the plot.)
Chan plays two twins who are separated by birth. They grow up in different worlds: Boomer is tough car mechanic and martial arts expert. John Ma is a great concert pianist. When Boomer runs afoul of a bunch of thugs, their paths (including the gangster who was responsible for their separation) cross again. This leads to a bunch of mistaken-identity sequences, but these drag on for too long. In the end, there's a confrontation between the gangsters and Boomer and Ma involving a fairly decent action scene.
Chan's performance is solid, but the editing of the film to create the "twin" effect is obvious. The badly-dubbed dialogue I can easily overlook, as this is how I've seen most Chan films and I think it adds a nice touch in and of itself. While I recommend renting this movie if you get a chance, I would not make this your first Jackie Chan film.