If you get the same score as your highest so far, your new info should be saved to the database. This allows you to change your comment, and reduce the time played. A basic fix is easy: change the > and < on this line to >= and <=.
PHP Code:
if ( (($player_score > $score) && $ginfo['highscore_type'] == "high") || (($player_score < $score && $ginfo['highscore_type'] == "low") && $score != 0) )