In fact, you could even use this game TO teach analyzing skills to youngsters. Of course, part of the fun IS when you figure out the strategy yourself. Warning: if you want to figure out these things yourself, don't read on! Just go play it.
I'm going to share some tips now for playing the Shopping City game. I reached 96% or 97% several times before succeeding in reaching 100% in the 9th level. I even wrote out how many percent I earned each day, and if I was falling behind my 'best play', I would quit and start that level over (which you can do by pressing the 'menu' button). I was not able to finish the last level without thinking about and analyzing several things. That strategy seemed to work alright in the beginning. For the most part, I played the game kind of randomly, building different kinds of stores randomly here and there - toy stores, boutiques, pet stores, restaurants, jewelry stores, and so on.