The problem with farces (for me, anyway) is that the spectacle of watching grown people acting like kids with high sugar levels in their bloodstreams wears a bit thin pretty quickly.
'Death By Hanging' is obviously very far from the Aldwych variety - not a glimpse of Brian Rix caught with his pants down behind a bedroom door. This is much more in the Dario Fo mode, getting the message across by knocking seven bells out of an authority which regards people from another country as inferior, and which has nonsensical rules about who they can or cannot hang. Oshima also cleverly adds interest by gradually opening out the mise-en-scene, first by the inclusion of a few props around a previously bare execution chamber to suggest a room where the condemned man used to live, then by a sudden eruption into the outside world.
Fo's 'Accidental Death Of An Anarchist' works because at just over an hour it doesn't outstay its welcome. Joe Orton's plays (the execrable film version of 'Entertaining Mr. Sloane' notwithstanding) work because of a relentless invention of plot and dialogue. 'Death By Hanging' has neither brevity nor a script which constantly appeals.
Then, for the last half-hour, the film changes tack completely. While the authority figures get boringly drunk, the condemned man and his 'sister' (he may not have had an actual sister; also the same actress plays one of his murder victims) philosophise endlessly about identity. You know a film isn't ticking the boxes when you keep looking at the clock.
The message is sound, the idea is good, the execution is left hanging.