Tetris DX

:Not to be confused with Tetris Deluxe, a game released for western mobile phones.
Tetris DX was a Game Boy Color game as an enhancement of Nintendo's original Game Boy Tetris, with two added gameplay modes (Ultra, lasting 3 minutes; and Vs. CPU, a match against the computer), a profile/save feature, and color graphics on Game Boy Color and above. In addition, the game's rotation system had a glitch which lets a player move any tetromino except O upward by holding the direction against a wall while rotating in the opposite direction.
== Modes ==
* Marathon (score maxes at 9,999,999)
* True 40 lines mode (not 40 "points" like in Tetris Worlds)
* Vs. CPU opponent
== Rotation system ==
The rotation system is an early version of what would become SRS.
Like in SRS, tetrominoes of width 3 rotate as if in a bounding square; unlike in SRS, L, J, and T start flat side up.
TDX first tries rotation about the center of the box (the blue circle).
If this fails, it tries rotation about an alternate center displaced by one cell (the gray circle).
For I, S, and Z, this center starts out one cell above the ordinary center; for L, J, or T, it starts out one cell below.
=== Wall climbing ===
This rotation system is exploitable, especially on low levels:
Charge DAS	
Rotate left	
Shift left (DAS)	
Rotate right aboutalternate center
This particular exploit was fixed in SRS.
=== Infinity ===
Ordinarily, Tetris DX lock delay follows step reset behavior: only downward motion under gravity resets the lock delay timer.
But rotation about the alternate center does reset the timer used for gravity.
This can be exploited by placing a piece in a corner and rotating it back and forth about the alternate center:
	
== See also ==
== External links ==
*Koryan's description of Sega Tetris, TGM, and Tetris DX rotation systems (Japanese language)
**English translation using Google Language Tools
Category:Games
Category:Handheld Games