public class Player
{
    // Constructor - guarantees that navi and chipset will never be null (unless later changed)
    public Player(Navi navi, ChipSet chipSet)
    {
        if (navi == null) throw new ArgumentNullException();
        if (chipSet == null) throw new ArgumentNullException();

        Navi = navi;
        ChipSet = chipSet;
    }

    public int Wins { get; set; }
    public Navi Navi { get; set; } // A local variable of the type "Navi" which is also named "Navi"
    public ChipSet ChipSet { get; set; }
}

public class Navi
{
    public const int HARD_LIFE_CAP = 2000; // Better as a static object of type "GameSettings" or something similar

    public Point Position { get; set; }
    public int Life { get; set; }
    public int LifeMax { get; set; }

    public Texture2D Sprite { get; set; } // Ideally there should be a separate class that contains per-sprite frame data
}