Hiring lots of actors and building elaborate sets (and then blowing them up) is expensive. So the directors of Jackboots on Whitehall used 12-inch action figures to scale down the cost.
Above is the trailer for that movie, which is a comedic alternate history of World War II. After trapping the British Army at Dunkirk, the Germans drill a tunnel under the English Channel and send an invasion force through into the heart of London. "Never," as the movie's Churchill says, "in the field of human conflict was so much buggered up by so few." Naturally, the Scots, led by a farmer voiced by Ewan McGregor, save the day.
via Geek Tyrant