GameOver! is an educational game designed to teach people about accessibilty—by counter-example. (Versions available for OS X, Windows, and Linux.)

The game comprises twenty-one levels, each of which violates a fundamental game accessibility guideline. An overview of the title, gameplay and violated guideline of each level is provided the "Game Levels" section of the site, while screenshots from some of the levels are illustrated in Figure 3. The player can select to play the game from the first level, or directly jump to a specific level. At the beginning of each level, its title is presented along with some guidance (e.g., the controls that can be used, the player's goal). In order to move from one level to the next one, the player must first lose three lives. Each time that a life is lost, one hundred points are subtracted from the player's score. At the end of each level, a famous quote related to the level's content is recited (a "punch line") and the guideline that was violated is displayed (see Figure 2). At the end of the game, a summary of the level titles and the corresponding (violated) guidelines are presented.

I regularly teach with counter-example assignments. They seem to be great learning tools—the act of creating objects that intentionally don't work both helps students see the effects of breaking guidelines and, in the process, helps make those guidelines more memorable.

[via Kotaku]