Certain versions of the Microsoft Mouse driver for DOS came bundled with a game called Boa (included alongside such utilities as Paintbrush and Mouse Menus). Boa takes the familiar premise of Snake games and turns it on its tail: the player is now the food, trying its best not to be consumed by an always-moving, ever-growing snake.

Our hero - a mouse - is controlled, as one might expect, with the mouse. The only objective is to survive as long as possible without being captured by the computer-controlled boa constrictor, which twists across the playfield in pursuit of its prey - touching the snake's body, or the walls, means death. The boa will get hungrier with time, and speed up as it tries to add you to its menu, fortunately enough, it is possible to temporarily freeze time to escape a tight spot. For every 500 points, the slavering serpent can be magically cut down to size and forced to start over.