protected override void Draw(GameTime gameTime) { GraphicsDevice.Clear(Color.Black); spriteBatch.Begin(); // tell the game management systems to render all of the game's entities (if the game has been started) if (spaceShipSystem.numberOfSpaceShips > 0) { projectileSystem.draw(spriteBatch); spaceShipSystem.draw(spriteBatch); asteroidSystem.draw(spriteBatch); explosionSystem.draw(spriteBatch); scoreSystem.draw(spriteBatch); } // render the menu (if appropriate) menu.draw(spriteBatch); spriteBatch.End(); base.Draw(gameTime); }