Spike Milligan was a beloved actor back in the day....and if you mention his name today, most Brits would recognize it. However, in the United States, Milligan never was especially well known. His radio and television antics were not brought to the States and no one would know he was a real institution in the 1950s-70s. As for me, I've seen him in a few skits from "The Goon Show" and as a guest star on "The Muppet Show"...and that's probably more than most Americans have seen. I didn't like what I saw, but to judge his talents only on my limited exposure would be unfair. He seemed to have a sense of humor that was an acquired taste...and I just didn't get to see enough of him to have much of an opinion. Sadly, in watching "The Great McGonagall", I still felt as if I must need to see him more, as I simply didn't enjoy his style of comedy and also had a bit of a hard time with understanding much of what he said (it really could have used closed captions). So, my advice is that if you are unfamiliar with his work, skip the film. It just isn't a very good introduction to his work due to the captions and that he and Peter Sellers only play one role in the movie--whereas what made both famous was their playing many different roles on TV and radio. It's just not a good introduction to his talents and I found the film to be tedious.
By the way, in this politically correct world, you should be aware that there are some black-face routines in the film.
By the way, in this politically correct world, you should be aware that there are some black-face routines in the film.