As far I have gotten everything has been really well polished, although exploration was sometimes a little confusing.
I cannot get past the spider chase in the Engine area. I've tried it around 30 times. Not sure if I am missing an item (like the cloak) or I'm just not quick enough.
Edit- Finally got past the spider in the Engine. That was brutal. I'm now going round in circles so I'll think I'll wait until there is a walkthrough available.
Great stuff!