Limbo
Limbo popped up in the news in 2006, if I recall correctly they had secured funding from danish authorities based on some concepts and were looking for developers. After that they pretty much went silent and it was easy to assume they never got anywhere for one reason or the other. When looking at indie game marketing it is easy to assume a non-transparent development process is a nonexistent one, although Phil Fish has some interesting points on the subject.
Anyhow, the game. Belonging to the puzzle-platformer genre it is hard not to compare Limbo to Braid in Particular. While Jonathan Blow was far along with the game design before David Hellman started working on the art of Braid, Limbo seems to have been developed around the visuals. Many puzzles rely on items being hidden in the background and the mechanics feel slightly less polished than Braid – a lot of the puzzles are physics-based and and rely on momentum, and as margins are fairly low it is sometimes hard to know if you are using an incorrect solution or simply are too slow.
Such occasions are rarely annoying for very long, though, and the game is beautiful and dark in a way few others in the genre dare to be. The years spent on this project certainly shows and it is well worth the time it takes to complete.