With games like Portal, the puzzle genre has made its mark on modern-day gaming, and this game keeps it going.
It's difficult to understand, but once you get going, you don't stop. That's the way all puzzle games should be, and it does so with charm and... well, screaming monsters.
The music is a tad repetitive (a few optional themes would have been nice, but that's probably asking too much, now isn't it?), and the sound effects may unsettle at first, but it does maintain a good pace. And it's not about that, it's about the puzzles.
And how addictive is this? With add-on gameplay from everyone else, it never can end, and minds will somehow bend this even more brilliantly in the future.
All in all, the best example of black-to-white negative space gameplay since the Shift series. Very well done!
(just copypaste :v)