How others will see it. Zelig is not among the most critically beloved of Allen films (Annie Hall and Manhattan routinely lead such lists, although I am also fond of Play It Again, Sam, The Purple Rose of Cairo, and Bullets Over Broadway. The Front is also really good, but Allen didn't direct it, only starred). It does, however, rank highly among critics within his prodigious film output. It also proved to be one of his more accessible movies, especially for those who appreciate nostalgia. Audiences could identify with a lead character whose motivation was entirely to fit in.
On the other hand, channel surfers of a recent generation, who encounter Zelig while navigating through the treacherous waters of shopping channels and reruns of mediocre sitcoms, will likely be briefly confused. Filmed in black and white, the footage deliberately mimics newsreel footage from its Jazz Age/Great Depression eras. Yet the narration implies the events took place in the past, indicating a later production date.
The satire is not always explicit. Getting the joke partly depends upon identifying Woody Allen, who is not usually disguised, as a comic figure who cannot convincingly pass himself off as anyone other than himself. Certainly, no fan of classic cinema who wanders into Zelig will be fooled for long.
How I felt about it. Is it plausible that a psychotic man with a need to assimilate would be nationally embraced as a popular hero by Roaring Twenties masses? If Zelig can defy the laws of science by gaining fifty pounds in five minutes, isn't this of greater interest than his pretending to be a doctor? If the naturally famous Zelig concluded a series of crimes under imagined identities, wouldn't this become known at the times of the incidents?
Or, is too much analysis being foisted upon a movie that isn't supposed to be serious? If so, then there's no need to note the film's serious message, that the compulsion to conform can lead to even a Jew supporting fascism, if that is the flavor of the month/year/decade.
If watching Zelig provides an insight into the twenties and thirties, it is interesting as such, but of course, films actually made during those years still exist, and provide the real thing. In the end, the contribution of Zelig is cultural: a word that personifies blithe conformity and assimilation. While that may not have fully been Allen's intention, it is not a bad outcome for a movie.