Gorillas

Gorillas, also known under the source code's file name Gorilla.Bas, is a video game first distributed with MS-DOS 5 and published in 1991 by IBM corporation. It is a turn-based artillery game. The game consists of two gorillas throwing explosive bananas at each other above a city skyline. The players can adjust the angle and velocity of each throw, as well as the gravitational pull of the planet.