On the flip side, during this time, Japan also produced more lighthearted monster movies that fell in line with American sci-fi and horror of the '50s. The mutated beasts in Godzilla (1954), Gamera (1965) and Attack of the Mushroom People (1963) reflected the post-war nuclear age, putting a campy spin on the country's deadly serious first-hand encounters with atomic energy during World War II.