Mine

Comparer class

public class Comparer implements Comparator<Score> {

	public int compare(Score score1, Score score2) {
		if (score1.getGuess()==score2.getGuess()) {
			if (score1.getPlayTime()==score2.getPlayTime()) {
				return 0;
			}
			return (score1.getPlayTime()<score2.getPlayTime())?-1:1;
		}
		else {
			return (score1.getGuess()<score2.getGuess())?-1:1;
		}
	}
	
}

/**
	 * @param args
	 */
	public static void main(String[] args) {
		Score score = new Score();
		score.setGuess(20);
		score.setPlayTime(20);
		Score score2 = new Score();
		score2.setGuess(10);
		score2.setPlayTime(20);
		Score score3 = new Score();
		score3.setGuess(30);
		score3.setPlayTime(20);

		ArrayList<Score> list = new ArrayList<Score>();
		list.add(score);
		list.add(score2);
		list.add(score3);
		
		Collections.sort(list,new Comparer());
		
		for (int i=0;i<list.size();i++) {
			System.out.println(list.get(i).getGuess());
		}
		
	}