I've finally made it through Fez, and am checking the forums for the third time (the first was for the security question solution and the second was for the "black monolith" solution... both after several hours of trying to figure them out on my own) and noticed that few people are discussing the leaderboards.
There are several people with over 400% completion, without even gaining 200 gamerscore in some cases, and for the life of me, I can't figure out how. Do you need to replay the game in stereoscopic mode or something? I see that at least a few people have glitched and ended up with an extra cube or something, but how could anyone possibly get every cube twice?
Also, I'm really kicking myself for not checking the forums sooner (or paying attention to what Vin said on the Bombcast)... knowing about the "special ability" in new game plus would have saved me SO much time. Especially in the rising laval level which took me over an hour because I platform like a one thumbed chimpanzee.