There is no way to make a perfectly secure savegame file, nor a leaderboard that cannot be exploited or spoofed. If Blizzard cannot prevent cheating, with all their efforts and millions of dollars, it is not realistic to think that an indie studio like LDW will be able to do it.

That being said we can discourage cheating or hacking, limit its effectiveness and take other 'bang-for-your-buck' measures. We are trying to mostly learn from what went wrong with Fish Tycoon's leaderboard (our first attempt!) and fix and improve as much as possible in subsequent releases.



<EDIT>
I just changed the leaderboard to be sorted by Fish Found, with ties broken by Money Earned. At first glance it looks pretty cheater-free. Thoughts?