Well I've gotta admit, I wasn't really sold after the frontpage article and reading part of the thread; could see it was well-liked almost universally but wasn't convinced it'd be for me. Tried the demo, and found it a lot harder than I'd expected... more so than I was eager to play further, even though I loved the use of the central mechanic.
Ultimately though, I saw the price just after I'd been paid and bit regardless. Best impulse buy of my life, bar none. The game is so much more rounded than I'd expected from playing a single level, with a real eye to detail and (as I should've believed from the frontpage review) no number of deaths in a row has wiped the grin off my face.
I hope any other sceptics will believe me when I recommend trying the demo and if you see anything you like, just dive in. A lot more than I'd expected and endlessly entertaining.
It seems to be like that for a lot of people. The game doesn't really look like anything special from screenshots or even videos, it's only when you play that you realize how flawless everything about the execution is, from the controls to the level design to the implementation of the gravity flipping mechanic. But it seems the "unflashiness" of it is what turns a lot of people off (which is one of the things I personally like about the game), at least that's what I could discern from some of the negative blog comments.
On a related note, I read a hilarious comment by some guy on Kotaku today arguing that Terry is a pretentious art fag because some of the enemies are moving words. No, seriously.

If it wasn't trying to be art, the words would've just been moving spikes. By bringing the definition into this, you've cemented that it is EXACTLY pretentious. Concerning the mechanics of the game, making the enemies in the game giant floating nouns does nothing to effect them. And when a game does something artsy-fartsy that only tinkers with the ascetics you get... Pretentious.