The screenplay was pretty dead other than for an occasional outburst from the leading characters when somebody stood on their toes if only metaphorically.
Douglas is Douglas. Jan Sterling is very good as well & takes everything Douglas throws at her including a couple of smacks in the chops. The screenplay is solid & although the ending is a bit over dramatic it should last the test of time for a while yet.
The first half, when Walken has more screen time, is better than the second but the entertaining plot idea does work thanks to the likeable cast and some good writing.
End to end action but it all gets a bit overwhelming and repetitive. A shorter version would have been better but the production values are very good throughout.