Amazing idea! Great intro, very interesting story and application. Mona Lisa overpowered, in a good way, it allowed me to beat the game. :D
I would have liked an option to upgrade the paintings, and to be able to see their radius. I also found it a little clunky when the level got hectic and I was trying to buy and place paintings quickly, maybe an option to click on an existing painting and duplicate it rather than going to the easel every time (or even for the easel to not have the zoom every time) would have made it a little smoother. Overall though it was a great game and I really enjoyed playing it!