There's some incredibly interesting and intricate line work here! The difference between the drawn concept and the digital is worlds apart. It's amazing the amount of detail or meaning that can be captured in just a few simple lines. I'm especially partial to the typewriter drawing and that slightly devilish looking bear character!
Line art and more simplified forms of drawing are something, believe it or not, I've yet to really master. There's definitely a lot of skill required in that.