It says it's the Anniversary edition on humble. So I guess it comes with that dlc, but no option to choose that.

It's a fuckin drivin game. You go aroun an aroun the track as Louie fuckin Armstrong in yo fuckin spacecar. The anniversary edition comes with few more cars from all your favourite racers like benjamin buttons and others like that with that fucked up sickness that makes people age the other way around. It's crazy this world. Sometimes I wonder how we get by. Day by day I suppose. Day by day.