Really good stuff. Easily one of the best takes on the theme I've seen so far. There are a few UI/ease of use issues. It is kind of unclear what you're supposed to do (but when you flip to the side-scroller mode it great, clever stuff), it's hard to distinguish between walls you can walk through in one but not in the other state. But overall it's a great experience, love the atmosphere as well. Music fits perfectly.
Too bad I couldn't finish it - missed one part somehow along the way.