Game class

package myFirstGame;

import java.awt.BorderLayout;
import java.awt.Canvas;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.image.BufferStrategy;
import java.awt.image.BufferedImage;

import javax.swing.JFrame;

public class Game extends Canvas implements Runnable {
    private static final long serialVersionUID = 1L;


    JFrame frame;

    public static Player player;

    InputHandler IH;

    public final static int WIDTH = 720;
    public final int HEIGHT = WIDTH / 16 * 9;
    public final Dimension gameSize = new Dimension(WIDTH, HEIGHT);
    public final String title = "myFirstGame";

    BufferedImage image = new BufferedImage(WIDTH, HEIGHT, BufferedImage.TYPE_INT_RGB);

    static boolean gameRunning;

    @Override
    public void run() {

        while (gameRunning) {

            tick();
            render();

            try {
                Thread.sleep(20);

            } catch (Exception e) {
                e.printStackTrace();
            }

        }

    }

    public synchronized void start() {

        gameRunning = true;
        new Thread(this).start();

    }

    public synchronized void stop() {

        gameRunning = false;
        System.exit(0);
    }

    public Game() {

        frame = new JFrame();

        this.setMinimumSize(gameSize);
        this.setPreferredSize(gameSize);
        this.setMaximumSize(gameSize);

        frame.add(this, BorderLayout.CENTER);
        frame.pack();

        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        frame.setVisible(true);
        frame.setResizable(false);
        frame.setTitle(title);
        frame.setLocationRelativeTo(null);

        this.addKeyListener(IH);
        IH = new InputHandler(this);

        player = new Player(10, 405 - 20);

    }

    public void tick() {

        player.tick(this);

    }

    public void render() {
        BufferStrategy bs = getBufferStrategy();
        if (bs == null) {
            createBufferStrategy(3);
            return;
        }
        Graphics g = bs.getDrawGraphics();

        g.drawImage(image, 0, 0, getWidth(), getHeight(), null);


        player.render(g);

        g.dispose();
        bs.show();

    }


}