More ideas? Yes, indeed! I'd like to share with you several intriguing gems I've recently unearthed from my idea notebook:
A game about guerrilla gardening, where you collect seeds and construct seed bombs. You would go on bombing runs where you try to turn vacant lots into gardens or break open pavement by putting certain kinds of seeds in the cracks. Like a collectible card game, it would support a variety of play styles that would appeal to different kinds of people. But instead of collecting cards, you collect different types of seeds, and instead of building decks, you strategically construct seed balls, and instead of dueling, you go out and try to plant your 'bombs' without getting caught. The concept also makes use of a slowly evolving world that changes as the plants grow, much like a turn-based strategy game such as Civilization. I think it could really fun.
Try making a physics-based strategy game that derives its gameplay and complexity from the basic physical rules rather than a complicated set of components and interactions. The purpose of this approach would be to make the game intuitive enough to pick up and play without a tutorial, which is very difficult for the typical RTS.
A game to help you notice the weather and how it changes. In this game the weather would have a big impact on the gameplay. Your character could be warmed up by the sun, or rained on, or snowed on. There would be a sort of 2D map of clouds blown around by the wind, so if you look up into the sky and see which way the wind is blowing, you can predict what sort of weather will be coming your way.
An art tool where you manipulate shapes or direct streams of particles, but instead of choosing options and colors with a toolbar, there are 'seeds' that appear. You can either ignore these seeds or cultivate them and use them as new colors or shapes in your drawing. There would be a sort of genetic algorithm at work, where new seeds would appear based on existing elements on the screen, while neglected seeds fade away. The idea is kind of similar to the way that new goo balls are actually crawling around on the structure itself in World of Goo, not in a menu.
Like the sound of these? Let me know what you think! :)
I especially like the first one, about guerrilla gardening, and I'll probably try to make it into a real game some day. Let me know if you want to help.