Tetris The Grand Master 3 Terror-Instinct

Tetris The Grand Master 3 Terror-Instinct, abbreviated TGM3 or Ti, is a Tetris game from Arika, part of the TGM series.

Difference from past games in the series
The grading system has undergone significant changes from previous games. The most notable change is the removal of an in-game score and grade display; they are only displayed after the end of the game, much like the secret grade in previous games. It is thought that the grading system rewards clean stacking and efficient recovery as opposed to raw speed or tetrises.

Scoring
Unlike in TGM, TGM2, and TAP, TGM3 advances the level further for a 3 or 4 line clear:

Easy
Easy mode has many similarities to the Normal mode of TGM2. It is designed to bring less experienced players into the game who may be intimidated by the high speeds and steep learning curve of Master mode and Shirase. During play, the game displays a guide, depicted by a hollow frame, designed to give players suggestions on where to place the active piece.

The game also shows animations of fireworks every time a line is cleared. The total number of firework shots ("Hanabi") during play is given at the end of the game, allowing experienced players to play a "game within a game" where the objective is to attain the highest number of fireworks possible. The number of fireworks can increase by larger number of line clears, combos (multiple consecutive line clears), and T-spin line clears.

Easy mode is cleared simply by reaching level 200. Play continues during the credit roll in 20G, with a boost in the number of fireworks shown.

Sakura
Sakura mode replicates the gameplay of Tetris with Cardcaptor Sakura Eternal Heart. The mode's objective is not to clear lines but instead plays similarly to Flash Point, where the goal is to clear every jewelled block in each stage as quickly as possible. The are 20 stages, and 7 EX stages, each progressively more difficult to clear efficiently. Some stages feature handicaps such as regularly flipping the playing field from left to right, or periodically turning non-jewel pieces invisible. The hold box is cleared between stages therefore it is not possible to hold a desirable piece for the following stage.

Score is not recorded as the mode is purely a time attack exercise. The player has a total time limit in which to complete the whole mode. Starting at 3 minutes the clock is extended with a time bonus for quickly clearing a stage.

Master
Master in TGM3 behaves very much like its predecessor in TGM2. Notable differences include the addition of a hold piece, 3 piece previews, and new wallkicks for T and I pieces. At first, these additions may make TGM3's Master mode appear easier than in TGM2, however this illusion is soon dispelled by a huge increase in speed which will cause all but the most experienced of players to struggle at later levels. Unlike previous games, the rate at which the speed increases is variable, and changes according to how well the player to doing. For instance, depending on the player, the game may enter 20G as early as level 300, or as late as level 500. Master mode will stop at level 500 with no credit roll if the player is too slow.

As mentioned earlier, the game does not display the player's grade during the game, and it is displayed only after the game has ended. The invisible challenge during the credit roll is back in TGM3, however unlike TGM2, surviving this does not necessarily lead to a Gm (Grand Master) grade. The Gm grade has not been attained by anyone so far, and the requirements are therefore unknown. Many players believe that the explanation for this, is that no GM grade can be obtained through standard play, although this has not been officially confirmed. However the Secret Grade GM is awarded for the secret ">" stacking challenge in the same fashion as previous games in the series.

Shirase
This mode follows in the footsteps of TA Death in TGM2, however the immense speed difference is immediately apparent, and continues to increase throughout. Shirase mode does not stop at level 999 as in TA Death and Master mode, and play continues right through to level 1300. Shirase also has other key features:

From level 500 to 1000, a line of garbage identical to the bottom row will spawn at regular intervals.

From level 1000 to 1300, every tetris piece that spawns is made of monochrome [ ] blocks.

Ichiro Mihara, creator of the series, has stated in his blog that levels beyond 1300 exist. Methods to reach such levels are yet unknown, as the 1300 barrier has not yet been broken, even at the current record clear times of 4 minutes and 33 seconds.

Grading is handled differently in Shirase mode. The game will award an S grade equivalent to the number of sections cleared; the highest grade being S13 for clearing level 1300. If the performance earned one or more "REGRET!" during play, the game will sometimes, though not always, award an S grade lower than the number of sections cleared. The exact trigger for a "REGRET!" has not been confirmed, but it is likely to be a penalty for slow play as it only appears at section changes.

The secret ">" stacking challenge works for Shirase mode also, despite significantly increased difficulty due to its speed. Secret grades awarded in Shirase mode start at m grades instead of the usual S grades.

The Shirase credit roll is a 20G, big piece challenge (all pieces are twice their normal size).

Shirase Mode Timings
Fall speed is fixed at 20G. Note that these values have been deduced through observation of gameplay videos and may contain inaccuracies.