import greenfoot.*;  // (World, Actor, GreenfootImage, Greenfoot and MouseInfo)

/**
 * Write a description of class Example here.
 *
 * @author (your name)
 * @version (a version number or a date)
 */
public class Example extends World
{
        // add (if you do not already have) these instance fields
private Clock clock; // sub 'Player' with name of player-controlled actor class
private int gameTime; // number of game-time units elapsed
private int gameTimer; // frame counter

    /**
     * Constructor for objects of class Example.
     *
     */
    public Example()
    {
        // Create a new world with 600x400 cells with a cell size of 1x1 pixels.
        super(600, 400, 1);

    }
    public void act ()
    {
        // in the world constructor
clock = new Clock();
addObject(new Clock(), 89, 99);
// in world act method or method it calls
if (clock.getWorld() != null)
{
    gameTimer = (gameTimer + 1) % 60; // adjust 6 to suit
    if (gameTimer == 0) gameTime++;
}
else
{
     // if game is over
    addObject(new Clock(), 60, 60); // now add it to the world
    Greenfoot.stop();
    // show value of 'gameTime'; in normal speed scenario, this will be approximate seconds
    // code to end game, reset level or start another life
}
}
}