I think they need to do something about "Cut Out Study" and "Cut Out Mastery" if they make another game. Once you max out both of those the game becomes too easy because of all of the money cutting down trees gives you.
Once you know the secret to winning the battles in seconds it gets waaaay too easy to beat and complete the game. The only thing that is a challenge after that is the mummy mode but only because it goes on forever.