Fields

in Map.cs and Game.cs, do this:

class Map
{
    public int Height;
    public int Width;
}

class Game
{
    static void Main(string[] args)
    {
        Map map = new Map();

        map.Height = 8;
        map.Width = 5;
    }
}

Notice the usage of public, if we make it private, it couldn't be called from Game.cs