The demo was excellent but I was already sold on the quicklook. 
Warning: Don't read the trophy list if you don't want to be spoiled!
 
IGN gave it an 85 "Rochard initially feels and even looks a bit like Shadow Complex, and invokes Shadow Complex's primary two points of inspiration as well: Super Metroid and Castlevania: Symphony of the Night. But it differentiates itself from all of those like-minded games with its primary concentration on puzzle-solving and platforming as opposed to exploration and combat. It's not to say that Rochard doesn't force you to do battle with foes or explore non-linear paths -- because it does -- but it emphasizes physics-based gameplay as opposed to the more familiar features of those aforementioned games." 
And they also say it's a 6.5hr game.

Yeah I've been looking forward to it as well, good to know people like it.