Mono (2005)

Mono (stylized as mono) is a video game by Binary Zoo in which the goal is to turn the entire screen either white or black. Described as "Part Asteroids, part Robotron, part Paint Shop Pro", the shooter was originally created as a test project for Binary Zoo's other games, DUO and DUOtris.

Gameplay
The player shoots alien-like colored blobs that when hit, color the background. There are three types of blobs (red, blue and green) and when they are hit, divide and become smaller until they are eventually destroyed. As the player colors more of the screen, the game becomes harder as the blobs start to shoot missiles at the player. The enemies' behavior depends on the background color below them. There are also power-ups for the player such as health, weapon and invincibility.

The game was created by Binary Zoo as a test library to help development of their other game DUOtris. Upon finishing, they decided to form it into an actual game and released it as a promotional freeware game.