List of TGM series bugs

This is a list of TGM series world bugs.

The Grand Master

Bugs for Tetris The Grand Master.

Gameplay

• Big Mode pieces will be truncated into half-rows if they are placed in row 22, since the playfield only has 21 rows.
• For the first piece of the game, you cannot charge DAS during ARE. Note that if you charged DAS on the previous credit, and keep holding that direction, then you will have DAS on the first piece.

Cosmetic

• If you mash buttons during the attract mode, you can glitch out the demo replay and cause it to top out.
• If you earn enough points to take you straight from S8 to GM (with GM conditions fulfilled), then the game will not play the "grade up" sound.
• The screen area of the game playfield is not perfectly divisible by 10, so some columns/rows have spaces that are slightly rectangular rather than square.
• The font used to display grade requirements, score, and levels has a maximum 32 characters onscreen at a time. It is possible to exceed this number, after which additional characters will not be rendered. This will some or all of player 2's level counter, making it almost impossible to jugde level stop boundaries.

The Absolute PLUS

Bugs for Tetris The Absolute The Grand Master 2 PLUS.

Gameplay

• Big Mode pieces will be truncated into half-rows if they are placed in row 22, since the playfield only has 21 rows.
• Grade points for combos have an off-by-one error in the table lookup, causing Tetrises to be nerfed and other line clears to be buffed. This was corrected in TGM3.
• Input drops in Doubles during lock frames. Even a DAS movement will pause for a frame mid-movement. This phenomenon has port priority. When player 1 locks, palyer 2 loses input that same frame. When player 2 locks, player 1 loses input the next frame.
• DAS charging does not stop after hitting the threshold. After 256 frames of charging it will rollover. If the rollover happens during active time, you can see a piece stop and recharge mid-movement.
• Line clears do not register in row 21. (Mainly can happen after receiving garbage in Versus and IRS'ing into a line clear.)
• Mirror Block does not mirror row 21.
• Mirror Block ends immediately without animation if the player does an-clear.
• Piece snipes from attack items in versus that occur on the last frame a piece is active will, after much delay, snipe the next piece immediately after spawning.
• Exchange Field fails if the attacker is receiving 180 Field. Despite the animation of Exchange Field they will still get their original stack 180'd.

Cosmetic

• The music will occasionally get stuck on a note. As the music continues it will eventually fix itself.
• Tetris Combos will fail to play their "clapping" sound effect, seen in TGM1.
• Secret Grade is detected in Versus Mode, on the last game of the credit.
• Sprite overflow is possible, especially if 2 players are playing Item Mode.
• Doubles Mode end of credit behaviour is strange. Under poorly understood conditions, it is possible to softlock the game or for the game to request the players to enter their initials twice.

Terror-Instinct

Bugs for Tetris The Grand Master 3 Terror-Instinct.

Gameplay

• Big Mode pieces will be truncated into half-rows if they are placed in row 22, since the playfield only has 21 rows.
• Killspeed that kicks in after 15 minutes of play does not invalidate the run for high scores. In particular, this means you can cheese otherwise-impossible section time records. TAP has a killspeed but does not have this bug.
• Easy Mode has a too-short lookup table for determining the credit roll combo bonus. The data found when overflowing the table is all zeros. The end result is that a combo of 9 or 10 doubles will have a x1.0 combo bonus instead of an 8 combo's x2.9 bonus.
• World Rules I piece wallkicks do not match the the Tetris Guideline.

Cosmetic

• Piece previews in Shirase 1000+ do not follow the same "flush with bottom" alignment of normal play. In particular the I piece is 1 row higher and may be difficult to see.