I wouldn't be surprised if most games in development ended up with a bunch of unused ideas, assets, and designs. That's just the nature of creating something, not everything you come up with is useful or neccesary. A good creative manages to recognize the essential aspects of a work and culls everything else.
Today, answering questions on his Formspring, Renaud Bedard of Polytron–the folks behind the indie darling Fez–revealed a bunch of stuff that wasn't used in Fez. It's kind of eye opening to see this all laid out on a Formspring question of all places.
So what was cut? Laser puzzles, which were dropped early after it was determined too difficult to implement. Heavy groups, which would have allowed players to have blocks fall down if supporting blocks were destroyed–which was fully developed, but there just wasn't a use for it. Same thing with chained explosions.
In an attempt to keep things interesting while you're walking over bridge sections, Fez put you on a different perspective for a while–kind of third-persony. Check that video here:
Lost features is a good name for all of this, yeah? Anyway, Other things that were dropped: pressure plates, motor blocks that catapulted you in a specific direction for mid-air puzzles. A lot of the things I've mentioned have videos available on the answered Formspring question, which also details these 'lost features' a bit more. Take a look!
Makes you wonder, doesn't it? What isn't used in other big games, I mean. I know what I'll be asking developers in future interviews!