I'm a 5th grade teacher in Cambodia, and one thing I can tell you is to try coming up with ideas in the same manner that children play. That's how I came up with the game I'm working on now. Kids will just grab toys and make up games and stories. You'll some kid who only has an racecar toy and some kid who has a dinosaur, but they somehow make it work and 'lo and behold, the story of Dino the Dinosaur and his trusty talking car, Bumper, is born. Try working within limitations. It does wonders for creativity, but don't sacrifice quality.