Tokyo, 1961 is a scenario that appeared in SimCity. In the scenario, Tokyo was under attack by a monster.
The monster that invades the city is a monster based on Godzilla, a Japanese dakaiju (giant monster) that made his debut in Ishiro Honda's 1954 film, Godzilla. He would later go on to star in over 30 more films including two American incarnations of the character.
If the player have the SNES version of the game, the city will be invaded by a giant version of Bowser Koopa from the Mario videogame series instead.