I enjoy mysteries, as can probably be deduced from the proliferation of Sherlock Holmes stories on this site, and enjoy clever- and sometimes silly- humour, hence the numerous Wodehouse blog posts. So I wanted to enjoy Clue, but I understand why it was a flop.
To begin with, the humour is not clever; the movie starts out with a running gag about dog poop and never really recovers from it. It could be classed as silly humour I suppose, because it is remarkably silly: the problem is, it's just not that funny. Nor are the characters particularly memorable; Lesley Ann Warren does her best to camp it up as Miss Scarlet, a Washington madam, but most of the characters are as flat as their pictures on the Clue cards.
The film doesn't work as an Agatha Christie-style mystery either, unfortunately. The plot-such as it is- consists of Mr. Boddy summoning all of the other characters, whom he's blackmailing for various transgressions, to his estate in the country for unknown reasons. He is subsequently murdered, and the unwilling guests who are trapped in the house attempt to discover how and why. Almost all of the rest of the movie involves them wandering about the mansion- frequently in the dark- as several other people are also murdered. It's not suspenseful, and it's hard to really care when various characters get knocked off because we don't care about any of these people in the slightest. It feels really repetitive... they split up in twos and wander about, the lights go out, there's screaming as someone finds a body, everyone runs to the scene of the crime and hysterically discusses, and then repeat.
There's no way to try to figure out who did what either because, despite the title, we're not given any clues. Eventually we're just told who the murderer is at the end in a manic monologue by Wadsworth (the butler, played by Tim Curry). Then, just when you think the movie is over, you are presented with an alternate ending in which one of the other characters actually perpetrated the murder. And then you are given a third ending with a different murderer again. I found this a bit odd, until I looked it up and found out that when the film was released in theatres, different endings played in different venues, so that who committed the murder depended on where you saw the movie. Maybe this worked on paper, but I can imagine that people viewing it at the time might find this concept a bit off-putting.
In the end, who really committed the murder? Who knows, who cares; the plot and people of this film regrettably left me indifferent to the question.