https://xgamers.gr/2013/07/%cf%83%cf%87%ce%b5%ce%b4%cf%8c%ce%bd-%ce%bc%ce%b9%cf%83%ce%ae-%cf%8e%cf%81%ce%b1-gameplay-%ce%b1%cf%80%cf%8c-%cf%84%ce%bf-killzone-mercenary/