Our Hero is sort of an aspie SuperCop who gets promoted to Sergeant and send to the tiny village of Sandford. He's not happy about this; he'd rather have stayed in London, even if it meant not getting the promotion. But the Metropolitan Police feel collectively like he's making them look pathetic and want him gone. Sandford hasn't had a recorded murder in 20 years, emphasis on the recorded. Their accident rate is amazing, and includes Our Hero's immediate predecessor. I have to wonder a little bit about the British and perfect looking little villages, given that this is by no means the first fictional one with a body count (the most recent was an episode of Torchwood a couple years ago, IIRC). But I don't wonder a lot, because we certainly have our share of rural horror her in the US, fictional and otherwise.
In general, there's a lot more of a plot here than in Naked Gun (that I recall, anyway), and the characters are much better developed. Most of the humor is character and/or plot driven -- it isn't just a framework for making in-jokes.
Absolutely worth the time. I'm still trying to figure out how to track down more work by the director or producer or whoever is responsible for this vast funniness.