This is science rather than rationality, but I'd like to see Maxwell's Demon the game, a Jezzball-like game where balls are bouncing at various speeds around a room with a divider in the middle. You open & close (or move) a gap in the divider to let balls through, with the goal of getting the faster-moving balls on one side and the slower balls on the other side. The hot side would get redder as it "heats up" (the average kinetic energy increases) while the cold side gets bluer, and the win condition would be a difference in temperature. More difficult levels would have more balls or would require a larger temperature difference.

An even more physics-y version could incorporate the ideal gas law and make it so that the divider gets pushed over a little bit every time a ball collides with it, so that the side of the room with more balls and/or higher average speed would tend to expand as the divider got pushed away. The win condition could involve both a temperature difference and a location for the divider.

There is already at least one Maxwell's Demon game out there, but the one I found isn't very good (as a game or as physics instruction). The balls are just red and blue - they don't vary in speed - and it's only one level where you have to get 100% separation by color.