game["id", "user":["id"]]

game.id and game.user.id

import ObjectMapper

class GamesData: Mappable {

    var id: String? = ""
    var user = [UsersData]()

    convenience required init?(map: Map) {
        self.init(map: map)
    }

    func mapping(map: Map) {

        id <- map["id"]
        user <- map["user"]
    }
}

import ObjectMapper

class UsersData: Mappable {

    var id: String? = ""

    convenience required init?(map: Map) {
        self.init(map: map)
    }

    func mapping(map: Map) {

        id <- map["id"]
    }
}