Thread: Misterious problem

Hello, I was creating a simple game, and I wanted to test program. But when I press "Run" on eclipse, nothing happens, "Terminate" button is active so I think, that program running. Here is my code:

import javax.swing.*;
 
public class MainClass {
 
	public static void main(String[] args) {
		JFrame frame = new JFrame("Catch Paulenas");
		frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		frame.getContentPane().add(new GameClass());
		frame.setSize(400,400);
		frame.setVisible(true);
	}
 
}

import javax.imageio.ImageIO;
import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.util.Random;
 
public class GameClass extends JPanel{
 
	//Declaring variables
	private int numberOfHits;
	private JLabel resultsBar;
	private BufferedImage target;
	private int targetX;
	private int targetY;
	private Timer timer;
	private int tryX;
	private int tryY;
	private Random rand;
 
	//Creating constructor, setting everything default
	public GameClass(){
		numberOfHits = 0;
		setLayout(new BorderLayout());
		setBackground(Color.WHITE);
		rand = new Random();
		getReady();
	}
 
	//Continue get ready for game
	private void getReady(){
		try{
			target = ImageIO.read(new File("target.jpg"));
		}catch(IOException e){}
 
		resultsBar = new JLabel("Number of hits "+ numberOfHits);
		add(BorderLayout.SOUTH, resultsBar);
		addMouseListener(new PanelListener());
		playGame();
	}
 
	//Playing game
	private void playGame(){
		while(numberOfHits < 20){
			timer = new Timer(rand.nextInt(2000)+1000, new TimerListener());
		}
	}
 
	public void paintComponent(Graphics g){
		g.drawImage(target,targetX,targetY,null);
	}
 
	//Listener for pressing buttons
	private class PanelListener implements MouseListener{
 
		public void mouseClicked(MouseEvent e) {
			tryY = e.getY();
			tryX = e.getX();
			if(tryY == targetY || tryX == targetX){
				numberOfHits++;
			}
		}
		public void mouseEntered(MouseEvent arg0) {}
		public void mouseExited(MouseEvent arg0) {}
		public void mousePressed(MouseEvent arg0) {}
		public void mouseReleased(MouseEvent arg0) {}
 
	}
 
	//Listener for timer
	private class TimerListener implements ActionListener{
 
		public void actionPerformed(ActionEvent e) {
			targetX = rand.nextInt(400)+1;
			targetY = rand.nextInt(380)+1;
			repaint();
		}
 
	}
}

Maybe you can see where is the problem, because with syntax is everything good, no errors.