I have to admit a passing addiction to a Flash game called Swinging Ball. Simple, and yet somehow intriguing.
Rolling and swinging a simple line-drawing ball around puzzles brings to mind the importance of mechanics. The images could have been anything, really — Spider-man would have been one obvious trapping. I know nothing about game designing, but I wonder whether it’s often done with boxes and balls and then fleshed out later, or whether it’s just as easy to develop the fancy graphics in tandem with the coding of the gameplay.