Killing innocents in finale
First, there are two major reasons the film works at all: James Coburn and composer Jerry Goldsmith.
The budget and overall production values of Our Man Flint look much cheaper than the Bond films made at the same era - which were filmed on location (not relying on grainy footage of Marseille, like Flint) and featured the masterful sets of Ken Adam. But the style of Coburn and better-than-the-film deserves score of Goldsmith lifts the film to success.
And what about that ugly ending: Cramden and the generals laugh and laugh as Galaxy Island gets pulverized - with hundreds of innocent "pleasure units" getting blown up by the heroic military.
Coburn's Flint just watches - and seems a little embarrassed by it all.