I have completed all the scenarios and challenges at least 4 times. I have unlocked all the 'challenge moce' items too and received all the items from awards for photographs etc etc... WITHOUT HACKS.
What's the point in buying a game that you hack? The whole point of playing the game is competely the scenarios and learning about how to build your zoo and look after your animals.
Once I complete all the scenarios I try and beat the time it took me to complete - there is always a challenge to be had - I never get bored of playing this game. I have now completed most scenarios within either 2 months or 1 year for the hard scenarios.
Keep with it - the more you play the more you learn, and the more you learn the easier it is to win all the scenarious and challenges!
King NANOOK rules my house!