I gotta say, this game really freaks me out. It just feels dirty - having windows pop up and out of existence as you move through each level. I have this primal instinct that something is going horribly wrong when I start to see tons of new windows flash about.
My personal reservations (and trauma) aside, this is a very cool, and very clever game. Taking an operating system's window mechanic like this and gamifying it is something I've basically never seen before.
Very clever puzzle game, still freaks me out, but clever nonetheless.