We Make Money Not Art found this McDonalds parody/educational game from Italian artists/activists Molleindustria. Burn down rainforests, inject cows with hormones, and make the kitchen a proper assembly line. The game is free and you can play online without downloading.
Some of Molleindustria's other games are a bit risque. Since they're all listed on the main page, you might now want to open the link at work (this post only links to WMMNA).