Mikael Håfström’s “Shanghai,” which premiered in China in 2010 and is finally getting a US release, has pretty vintage cars, costumes and décor, plus the ever-welcome Gong Li, all lensed in fine neo-noir style.

But Hossein Amini’s script leaves good actors like John Cusack, Ken Watanabe and Chow Yun-Fat flailing. It’s a spy saga set in 1941, with too many characters divulging vital information in bars, casinos and embassies, in between gunfire, knife fights, drug addiction and a bit of sex.

I wish that people imitating 1940s films like “Casablanca” would ditch flashbacks and tough-guy voice-overs, and instead try to mimic swift, lean narrative.