Looks like fun. Reminds me of Prey a bit but, IMO looks better because they are using some really good field of depth, and motion blur effects in game... have a look.
http://www.3dgamers.com/dlselect/games/halflife2ep2/portal_teaser01_720p.wmv.html
https://www.youtube.com/watch?v=QpdCi5XpCsE
http://www.3dgamers.com/dlselect/games/halflife2ep2/portal_teaser01_720p.wmv.html
https://www.youtube.com/watch?v=QpdCi5XpCsE