Game class

package com.packag;

import javax.swing.*;
import java.awt.*;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.awt.image.BufferedImage;

public class Game extends JPanel implements KeyListener, Runnable {

    public static final int WIDTH = 400;
    public static final int HEIGHT = 630;
    public static final Font main = new Font("Bebas Neue Regular", Font.PLAIN, 28  );
    private Thread game;
    private boolean runnig;
    private BufferedImage image = new BufferedImage(WIDTH, HEIGHT, BufferedImage.TYPE_INT_RGB );
    private GameBoard board;

    private long starTime;
    private long elapsed;
    private boolean set;

    public Game(){
       setFocusable(true);
       setPreferredSize(new Dimension(WIDTH, HEIGHT - GameBoard.BOARD_HEIGHT));
       addKeyListener(this);

       board = new GameBoard(WIDTH/2 - GameBoard.BOARD_WIDTH/2, HEIGHT);
    }

    private void update(){
        board.update();
        Keyboard.update();

    }

    private void render(){
        Graphics2D g = (Graphics2D) image.getGraphics();
        g.setColor(Color.white);
        g.fillRect(0, 0, WIDTH, HEIGHT);
        //render board
        board.render(g);
        g.dispose();

        Graphics2D  g2d = (Graphics2D) getGraphics();
        g2d.drawImage(createImage(WIDTH, HEIGHT), 0, 0, null);
        g2d.dispose();


    }

    @Override
    public void run() {
        boolean shouldRender = false;
        int fps = 0, updates = 0;
        long fpsTimer = System.currentTimeMillis();
        double nsPerUpdate = 1000000000.0/60;

        //last update time in nanoseconds
        double then = System.nanoTime();
        double unprocessed = 0;

        while (runnig){
            double now = System.nanoTime();
            unprocessed += (now - then)/nsPerUpdate;
            then = now;
        }

        //update queue
        while (unprocessed >= 1){
            updates++;
            update();
            unprocessed--;
            shouldRender = true;
        }
        //render

        if (shouldRender) {
            fps++;
            render();
            shouldRender = false;
        }
        else{
            try {
                Thread.sleep(1);
            }catch (Exception e){
                e.printStackTrace();
            }
        }
        //fps timer
        if (System.currentTimeMillis() - fpsTimer > 1000){
            System.out.printf("%d fps %d updates", fps, updates);
            System.out.println();
            fps = 0;
            updates = 0;
            fpsTimer += 1000;
        }


    }

    public synchronized void start (){
        if(runnig) return;
        runnig = true;
        game = new Thread(this, "game");
        game.start();
    }

    public synchronized void stop(){
        if(!runnig) return;
        runnig = false;
        System.exit(0);
    }
    @Override
    public void keyTyped(KeyEvent e) {

    }

    @Override
    public void keyPressed(KeyEvent e) {
        Keyboard.keyPressed(e);
    }

    @Override
    public void keyReleased(KeyEvent e) {
        Keyboard.keyReleased(e);
    }

}