The Earth Defense series is a series of three arcade games developed and published by Sega. The first two games in the series, Earth Defense 1 and 2, were released in arcades in 1988 and 1990, respectively. Earth Defense: The New World was released in 1992 and is the last game in the Earth Defense series. The objective of the game is to defend the planet from an alien attack. The player can use a variety of weapons to fight the aliens, including artillery, tanks, and planes. The game has three difficulty levels, and the player can also build their own base to defend the planet.