Computer: "Wafflism is behavior towards the state or existence of waffles and how it affects the user of the term or those affected by its use, typically in a negative demeanor. Would you like examples?"
Me: "No, I think I know enough."
Computer: "Understood."
*shuts down computer*
Me: "...and so it begins. Time to take down the pile of waffles." *maniacal laugh*
Well... Now that i think of it there is a simulator game called Evolution which is pretty simple. All it is is you make a model of living thing with joints, bones and muscles and the game will give it an AI and you can try to get it to either climb well run well, or something else i think. But basically you make it and i think it evolves the design to better suit its task (running climbing, etc.). Not a sandbox but it does support a bit of creativity.