thatgamecompany did flOw, Flower, and Journey as part of a 3 game deal with Sony. flOw was originally released as part of Jenova Chen's master's thesis and was reworked for their first release for Sony. This unfortunately means they are likely to remain exclusive to the Playstation3 platform for the foreseeable future.
Ico and Shadow of the Colossus were developed by Team Ico, led by game designer Fumito Ueda, and were released on the PS2 years earlier.
I know I read somewhere where they openly acknowledged their influence in the making of Journey, but it seems readily apparent that the emphasis on minimalism, emotional and musical immersion, and artistic stylizing are shared by both the development teams. I'll try to find the quote, it said that Fumito Ueda had played Journey and enjoyed it also.