Fez

Far north on the map west of the telescope is a room with a device which displays Tetris shapes when Gomez moves. Next to it is a statue with some kind of scribbling which you've likely seen through the game. The scribbles are Tetris code. They're to mark places where you can earn reveal secrets/open doors by cracking the code and entering in the specified command sequence.

I'm going to try to explain this visually with Xs and Os, where the X denotes a part of the block shape and the O is a space. I'm using letters for spacing to try to preserve the formatting just in case.

Press UP

oxo
xxx

Press DOWN

xxx
oxo

Press LEFT

ox
xx
ox

Press RIGHT

xo
xx
xo

Press JUMP

xx
xx

Press RIGHT TRIGGER

oxx
xxo

Press LEFT TRIGGER

xxo
oxx

The problem here is that this doesn't quite match up to what you see on the display. The code as written on the stone has been turned counter-clockwise, thus what initially is displayed as

xo
xx
xo

and would require a RIGHT press is actually

oxo
xxx

and requires an UP press. Got that? For example, the initial truncated sequence of

xo
xx
xo

xx
xx

xo
xx
ox

requires UP JUMP RIGHT TRIGGER to pass. The reason here is that the squiggly pieces are drawn vertically on the stone, but you've only access to horizontal ones. So, to make things easier on you, go ahead and jot down the notation on the stone on a piece of paper, then flip it counter-clockwise, then write down the controller input sequence over the symbols.

(There's a classroom behind the ancient door that requires 16 cubes to open which explains how to break apart the Tetris blocks and rotate them as explained above.)

There is a limited time window for this to be entered. It's nothing terribly strict, but you'll miss out if you're fumbling through the solution, trying to remember what goes where, and making mistakes.

Go north, and at the final branch, go west. (In the level with the telescope at the top, go in the non-telescope door. Then go in the tree.)

You'll see one of those anti-world puzzles with Tetris pieces (tetrominos) at the top. Here's a glossary for their names: http://tetris.wikia.com/wiki/Tetromino

Atop the platform, each controller button shows a tetrad on the grid:
* D-pad (up/down/left/right) shows T-block tetrominos with the bump in the d-pad direction. Try it.
* Jump ("A" button) is the square, the O-block.
* LT is the Z-block.
* RT is the S-block.
(You can figure this out from trying it yourself.)

Tilt your head to the right and read the inscription on the pillar nearby. Write out the tetrominos and convert them to buttons. It's easiest this way. Get the combination right and a sound will play.

My combination was up, A, RT, LT, A, down, LT, RT. Is everyone's different?