A competition for a good cause: http://www.retroremakes.com had a competition for handicapped people for making a one button game. The game should be control by one and only one button. This requires some interesting concepts for the game idea and the controls.
My entry: Ketchup Factory!
Tomatoes are on the loose! Try to withstand the attacking tomatoes as long as possible! Keep a button pressed to rotate your vegetable laser, release the button to smash the tomatoes. But they're coming in faster and faster. How many can you turn to ketchup? Find out for yourself!