Johnny Barrett’s review published on Letterboxd:
A singularly unique horror movie, that works because of it's oddness despite a lot of weird decisions and flaws. It's no wonder the remake is a famously terrible movie; since this movie walks a tightrope of being too silly and having a strange but unsettling tone. So much of the movie is dedicated to building the small little details that make up Summersisle, to the point where a woman breastfeeding while holding an egg for seemingly no reason doesn't seem out of place. Another aspect that is carried well (that is essentially dropped in the remake) is the central theme of culture shock and religious dogma on both sides. The inspector is offended constantly as affronts to his morals, and for a while we (or at least me) as the audience don't see anything too bad about the residents even though we know something is altogether wrong.
That sense of "offness" is the real key here. The garish 70's designs mixed with old pagan ones creates a mildly sickening look that even though I found it unpleasant from a design aspect it really helps making you feel uncomfortable throughout. Acting and direction-wise there isn't too much to say, other than Christopher Lee obviously stealing the show.
Since this is such a music-centric movie, the soundtrack plays a really vital role in balancing the story out. Unfortunately, this is where it falters a lot for me, as some of the music is atmospheric folk tunes and the rest of it is awful garbage. The named song from the credits is really horrible, but it at least only appears breifly. This is counteracted a little by the really great Maypole song/dance as well as the initial pub jig, but the music is where the movie falters most often.
The ending is the real showstopper, as everyone who's seen this will agree. The Wicker Man itself is pretty impressive in practical terms, and the idea of battling zealots drives the themes of the movie home in a satisfying way. The satisfaction of the ending helps heal up a lot of the mistakes early on and I think is the main reason this is known as a classic. Give it a shot, there's not much else like it.