Tried it for a while, its a nice mix-up on a balance/stacking game. Really like the City/country theme you got going, the stereotypical French-music was also a nice touch.
I could not however get past the first challenge. I liked the idea of the challenge to stack a collection of buildings, but it was way to hard right of the bat. I feel when a game first introduces you too the mechanics it should be a relatively easy challenge, to get in to the flow. However right now with the the starting balancing-pillar being so tiny, I could not get past the third building placement, it just got very frustrating. Maybe make the first level start with two supporting pillars, then make them smaller/less as the levels progress. You could even have a level that has two separate platform etc. to spice things up.
I also think you rely a bit to heavily on the pure-physics-system, as it makes saving a collapsing city almost impossible if it starts to wobble or one building falls of. With some tweaking you could have added a almost "rubber-band" mechanic so that if you manage to balance it again the game "helps" you a bit. Not to much mind you, there should obviously be a "breaking-point" when the thing will always fall, but some help to get the thing to stabilize again would feel nice and more game-like. Otherwise I feel its "just" a battle against the physics-system rather then a stacking challenge, if that makes sense?
Anyway! A nice classic game that fits the theme well! Keep on the good work.