Haven't checked the pc port or anything but I loved Shadow Complex when it dropped on 360. I remember there was an achievement or something for beating it in 24 hours? So me and like 3 friends had a party chat session for literally like 18 hours running through it to see who could do it first.
The PC Remaster just ports it to Unreal 4 and adds higher resolutions, etc. But it does include some new achievements and challenges to do. I think they may have tweaked one puzzle that had like a 1 in 10000 chance of screwing up in the original.
The remaster was mainly done for a number of non-financially driven reasons, like testing Unreal 4 features, their animation system on UE4, getting it on PC and Xbone/PS4, seeing if there was interest for and prepping for a sequel, etc. That's why they gave it away for the first six months or whatever. David Mustard gave an interesting brief interview about it in response to game journalists not understanding why they were doing all that for free* but I can't seem to find it now. Was on Kotaku or Polygon I think.
*I remember it because he pointed out that it was a six year old game, and the interviewer was like "but UbiSoft is remastering even older titles and selling them for $60?!?" and he was like "so?"
