One of the most bizarre films ever made. When he died, Bruce Lee left behind some fighting footage for a movie he never got to complete (which was to star George Lazenby incidentally). Golden Harvest decided they couldn't let it go to waste, so they brought in Robert Clouse, director of Enter the Dragon, and cobbled together a plot about a Bruce Lee style actor who upsets the mob, who then try to kill him... so he goes into hiding and seeks his revenge via way of various disguises. They added a bunch of Hollywood actors to help make it more appealing for the world market.
Now that's actually a decent idea for a movie - its similar to the premise of Return to Eden, and is based in strong emotion (desire for revenge, watching your partner think you are dead). But the kick off is weak - I didn't buy that they would go to all this trouble to shoot Lee just to prove a point. (I wish they'd had more history with Lee, like was a childhood friend he owed a favour too or something).)
And the doubling of him isn't very effective - Bruce Lee was so distinctive it's really obvious when someone is impersonating him. They try to add extra Bruce by putting in clips from Way of the Dragon and Fists of Fury but that makes things even more distracting.
Because Bruce Lee made so few movies as a star this is still worth seeing. The fight stuff at the end is pretty good, especially the bout he has with Kareem Abdul Jabar. Colleen Camp does the best she can with her role as Lee's girlfriend (a singer who at one point is so deranged with grief she decides to shoot his assassin). Gig Young adds some professional sheen as his journalist friend, Dean Jagger is fine as a mob boss, and Hugh O'Brien good as a baddie... until he has to do kung fu. I really liked this as a kid but it so didn't hold up.