public class Game1 : Game
{
  [...]
  protected override void Draw(GameTime gameTime)
  {
    [...]
    spriteBatch.DrawString(_gameFont, $"Score : {_score} pts.", new Vector2(20, 20), Color.White);
    spriteBatch.End();
    base.Draw(gameTime);
    [...]
  }
  [...]
}