Napoleon's Dictionary is a pretty good early Lupin special.
Lupin is after Napoleon's Dictionary because, as you could imagine, it has information that can lead to a treasure. Lupin enters a old fashioned car race with the dictionary as the prize, and his gunslinger partner Jigen comes along for the ride. Fujiko is of course also after the treasure, and the classy samurai Goemon shows up to help his friends.
This is one of the less elaborate Lupin stories, feeling more like an extended episode of the TV series than a movie. This is not necessarily a bad thing, but it does lack the epic feel of some of the other specials.
We have some very fun stuff from Goemon, he's especially eccentric in this one. Zenigata and Lupin have some laugh out loud scenes handcuffed together, and Jigen like usual is the straight man to balk at Lupin's antics. Fujiko does have less screen time in this than I'd like though, her fun sex appeal is always a nice touch.
The plot in this one does give some brief attention to Lupin's grandfather Arsene Lupin, and father Lupin II. This is a nice touch for fans of the series.
All in all, this is your typical Lupin caper. A solid entry, but not one that stands out. It's a fun watch, with a laid back feel, jazzy music, and some hilarious comedy. Lupin fans, you may as well give this one a watch.