I think all the games sold by this guy are stolen!
it's really sad to see this :-(
You should report this crook to Envato (https://help.author.envato.com/hc/en-us/requests/new), because your game is sold with the source code and a distribution license... So honest people or honest companies can buy a license and distribute your game thinking they are in compliance with copyright which is not the case...
And maybe you could also sell your game on CodeCanyon (I would definitely be interested) :-)