This is not a game, but I hope that you'll still have some fun messing around with it. I programmed it mainly to experiment with the file saving features available for FP10.

When complex numbers are coloured according to the rate at which they escape via iteration through f(z) = z² + c, some beautiful, fractal-like images can be produced. Use this programme to create a Mandelbrot set poster. (The save dialogue for the final poster takes a moment or two (or three) to come up when you click save, so please be patient. The final posters tend to be around 4 MB in size.)

Use the UP and DOWN arrow keys (or the mouse wheel if the page is fixed) to zoom in and out. Click "Stamp" to add the image to your poster. You can save the images as you go along or save the entire poster as one file after the 12th image has been stamped. Print it out and use it to decorate your mathematics class!