Can we use Facebook scores API where least score is the best score. e.g. higher times in solving a puzzle are not "better" times, these stories are contextually incorrect when they compare user's scores. Is there any solution for this problem.
Why not simply change the approach - in fact less time spent on something is better, so user should get more points. So, if you have a time limit in your game you can set points for a user as maxTime - actualTime.
I used this approach when I created a quiz game with 10 seconds to answer each question and it was perfect for this situation and I think it would fit your game, too.