public class Entity
{
    public List<IComponent> Components { get; set; }

    public Entity()
    {
        Components = new List<IComponent>();
    }

    public void Update(float elapsed)
    {
        foreach(var c in Components)
        {
            c.Update(elapsed);
        }
    }

    // BLA BLA BLA ADD COMPONENT GETCOMPONENT<T> REMOVECOMPONENT<T> BLA BLA BLA
}

public interface IComponent
{
    void Update(float elapsed);
    // BLA BLA ETC BLA BLA
}