EcoMahjong takes place in the beautiful town of Greenville. However, it's not as beautiful as it used to be. The Extracting Company Evil, Inc. has polluted the local river and land, causing Greenville to be covered in smog! The Walker family has taken it upon themselves to restore Greenville back to normal, but they need your help! Join the Walkers and restore the ecosystem in Eco Mahjong!