Consider a new game Packaging Man, which its creators bill as follows: An environmentally themed video game ... to raise awareness about the destructive impact fast food paper packaging has on Southern forests. The game which is a new take on the classic video game, Pac-Man, follows the exploits of the hero Packaging Man as he works to save forest creatures by collecting excessive packaging and recycling it, all the while avoiding the "evil" fast food corporate executives.
If you play the game, you'll see that it is a straightforward Pac-Man clone, with a few colors changed. An animated introduction is the only aspect of the work that attaches the theme to the gameplay. It's not even a re-skin; it's just Pac-Man with a bizarre intro.