Not a game per se, but definitely fun to play with. Infinite Wheel is a series of Flash movies by Jim Johnstone that borrows samples from various 'Dub' artists and presents them in a virtual playground in which you click, drag, and mouse-over the unique and compelling interactive controls to create your own dub music mixes.
For our final project for MUMS (Multi-User Media Spaces), Jonathan Atleson and I wanted to create a predator-prey simulation in Director 3D. Our objective was to show how naturalistic behavior can emerge from simple intelligent agents. You will need the latest Shockwave player installed to view the simulation.
File this one under interactive Flash tools for creative expression. Scribbler is just one of many interactive "toys" available at Zefrank.com. This "generative illustration toy" allows you to draw with the mouse in the window, then Scribbler takes over and creates its own drawing on top of what you've drawn. There are even interactive controls that you can set and tweak to your heart's content.
This little Flash avatar creator is a versatile and has several options to help you create very unique characters. Create a face of your own that fits your unique personality, then do a PrintScrn and paste into your favorite bitmap graphics program.
Thanks to WeezBlog for the link to a very cool site, Typorganism, where I played with all sorts of interesting type-related interactivity in an elegant Flash presentation. There is a visual composer feature which allows you to play with various palettes of sounds, organizing them as you might use a sequencer. If you like what you hear you can eve...