Thanks for the hint to Insanely Twisted Shadow Planet - looks very nice.
But, I don't see any similarities - because the main twist in In The Dark seemed to be IMO the avioding of and walking on light.
Concerning the "Nice concepts, but not great execution" - I didn't have a close look at the first video, because I felt like you, but I liked the Gameplay Video very much.
On the other hand, I recently bought "Limbo" - it was extremely promising concerning gameplay and grafics - but turned out at the second half as slipping into old gameplay conventions and had almost no story, and thus it was very disappointing although the grafics and sound was fantastic.
So, I didn't care in case of this game about grafics.