There are huge amounts of reference points that foreshadow the work of the likes of Monty Python, the wisecracks come thick and fast from Groucho (occasionally not too intelligibly; his thick accent and rapid fire enunciation can be impenetrable).
For me though the best thing about this marvellous piece of filmed theatre was the routines shared between Chico and Harpo as Chicolini and Pinky the incompetent spies. Harpo is genuinely funny in a laugh out loud, slapstick way. Some people don't go much on slapstick; perhaps I'm just unsophisticated, but when it's done as slickly as Harpo and Chico can do it - wow!
Other scenes take a swipe at Busby Berkley's work and there's a definite sideways look at Gilbert and Sullivan.
I honestly can't remember any thought of a film club scale, I think that Shazzrooneypoos thought it a bit of a curate's egg (good in parts); Slocombe didn't sound too keen; Frankenkeith laughed in all the right places. I think we were all quite taken aback by the Marx Bros' onslaught.
Would I go out of my way to watch another Marx Bros film? Probably not - but watching this did give an insight into how modern comedy was born; it's surprising how up-to-date a lot of the humour is in this film.
Here's a scene that had me howling. Judge for yourself - the "business" that Harpo (the silent one with the career-long running gag of using scissors) gets into this routine is outstanding. Imagine the rehearsals to achieve the wonderful timing.