If you pay very close attention, you might be able to follow about 50% of the plot, but do you really want to put so much effort into watching a comedy? Some of this editing is quite clumsy: the first pre-credits scene, a short one, features Sellers, as if the producers are pointing out to us that he is indeed in this movie (he doesn't show up again until 40 minutes later). In addition, actor Sellers, the nominal star, left before completing all his scenes, so his personal trajectory is less than smooth - as if a scene is missing, naturally. A heady brew and, predictably, largely incomprehensible.
The original intent was to have each director do their own little mini-movie spoof - an anthology they ended up editing everything together into one so-called film. Get everything but the kitchen sink (literally, in the over-the-top climax). Of course, this wasn't the first such effort others already began the 'Our Man Flint' duo film series and 'The Man From UNCLE' on TV was in full swing, not to mention 'Get Smart.' So, how to outdo them? Get five top notch directors. So, the intent here was a spoof of the then-wildly popular Bond/spy mania of the mid-sixties. This was the Bond title unable to be used by the filmmakers of the regular Bond film series, until the end of the century (they finally got to it for the restart in 2006).