Fields of Green: Crop Circle is a promotional expansion that adds new cards to the base game Fields of Green. These cards, known as Crop Circles, were originally distributed during the Essen 2016 game fair and to Kickstarter backers. The Crop Circle allows players to strategically reorganize their farms by moving a location to another empty space and placing the Crop Circle in the original spot. This mechanic adds an extra layer of planning and flexibility to the game, making each match unique. With mechanics like simultaneous action selection and tile placement, Fields of Green: Crop Circle is an interesting addition for fans of farming and city-building games.