I keep an idea notebook, which I make sure to write in every day. Sometimes I come up with some interesting ideas for games. Here are a few I thought I'd share:
A story or game about someone who is used to living lightly and is very self-sufficient, who finds a child or animal and chooses to care for it. That could result in some interesting tensions, where one's way of living has been optimized for solitary life, and then must suddenly change to accommodate another. It could be interesting as a minimal game like Passage or Gravitation. Another interesting twist could occur when for some reason it is time to give up the child, and discover what it's like to go back to solitude, or create a new lifestyle.
A game about freedom and proactivity and breaking out of the control of the game itself, based on the idea that you should "vote with your money." It could be a shooter where you can buy upgrades and such, but the money you spend goes to whatever faction that is selling the item. Different factions control and deploy enemy ships, and the more money they have, the more powerful they are and the more the other factions seek to imitate them. It could be a genetic algorithm influenced by your spending choices. When you first start the game, it seems that you have no choices, where one wrong move means instant death. But you can slowly expand your circle of influence by spending your money wisely.
An iPhone game to promote basic visual awareness, where you choose a color for the day, and try to notice all occurrences of that color as you go about your activities. When you see the color, you show it to the iPhone's camera to have it counted toward your score. The more the better. Difficulty could be varied by changing the threshold for detecting equivalent colors. The more precise you have to be, the harder it is.
An audio-only game where there are objects positioned along a horizontal line, whose positions can be determined by the stereo sounds they make. You could move a turret left and right and shoot, like Space Invaders. Your turret and all projectiles would make sounds also, so you can track where they are and get a feel for how the sound and input map to the virtual space. Distance could be represented by volume. Maybe even pitch and texture and other things could play a role, in the background. It could be a full shooter in sound, without graphics. Maybe it could be made musical, to be like music with meaning. And when you upgrade your weapons or your turret, they would sound cooler than before!
Any thoughts? I particularly like the "vote with your money" game and the audio-only shooter. Maybe I'll have a chance to make them sometime. Let me know if you want to use the ideas yourself - maybe we can collaborate!
More cool ideas on the way! :)