Tetris Worlds

Tetris Worlds was the game that became the basis for the Tetris Guideline.
Like other Guideline games, Tetris Worlds has a relatively long lock delay with infinity, a hard drop without lock delay, and full SRS. It shows three next pieces on GBA and six next pieces on other platforms. Unlike later games, the game had an autorepeat feature for the rotation button; holding down the rotation key kept the piece spinning continually. The game was also the first Tetris game to feature an American female voice whispering to you during gameplay. 
== Tetris mode ==
Classic game with then newly standardized SRS.
Goal of each level L is to earn 5*L points:
Line clear 	Score
Single 	1
Double 	3
Triple 	5
Tetris 	8
Tetris B2B 	12
T-spin zero 	1
T-spin single	3
T-spin double	7
T-spin triple	6
== Square mode ==
Much the same as The New Tetris (which see), except Tetris Worlds has a longer lock delay, no lock delay on hard drop instead of firm drop, full SRS, and (on platforms other than GBA) five next pieces.
Square mode does not use the Random Generator algorithm. It has a greatly increased probability of dropping the same piece several times in a row. This gives the player more opportunities to construct monosquares (4x4 squares made with only one kind of tetromino; called Pure Squares in this game), but also increases the probability of long stretches without a needed piece.
For details on the 4x4 square mechanic, see The New Tetris.
The goal for each level L is to earn 10*L points.
Line clear 	Score
Single 	1
Double 	3
Triple 	5
Tetris 	8
Contained monosquare 	+ 10
Contained multisquare	+ 5
T-spin zero 	1
T-spin single 	3
T-spin double 	7
T-spin triple 	6
*T-spin line clear causes avalanche, just as in The New Tetris, except using SRS T-spin rules
*Extra lines after a T-spin avalanche: not determined
== Cascade mode ==
Nearly identical to the fan game Quadra. After a line is cleared, each tetromino falls as a separate piece under the influence of gravity, and it is possible for pieces to fall and fill in gaps, creating a cascade.
Goal of each level L is to earn 5*L points. The score for each step n of a cascade, where n = 1 to 20, and L lines are cleared:
:(L + n) * 2 - 3
For example, a tetris-double-single combo scores
#(4 + 1) * 2 - 3 = 7 on first step
#(2 + 2) * 2 - 3 = 5 on second step
#(1 + 3) * 2 - 3 = 5 on third step
for a total of 17 points.
Tip: This mode is easier than standard Tetris. S and Z cascade makes it easier still.
== Hotline mode ==
Rows 5, 10, 14, 17, 19, and 20 (counting from the bottom up) are highlighted. Only lines cleared in these rows are counted toward the score. 10% of tetrominoes are multi-colored, and it has cascade mode's gravity.
Goal of each level L is to earn 5*L points:
Row	Points
5 	1
10 	2
14 	3
17 	4
19 	5
20 	6
The line clear with the highest possible score is a tetris or hurdle in 17, 19, and 20, for a total of 15 points.
So it's best to create a bit of intentional garbage to boost your stack to the higher-scoring top of the field.
== Sticky mode ==
Much the same as The Next Tetris. 20% of tetrominoes are multi-colored and break into smaller pieces of separate colors when they lock. Blocks of the same color glue themselves together; any contiguous group of the same color with 25 or more blocks disappears. Anything with nothing supporting it falls, just as in Cascade mode.
Each level L starts with L + 1 rows of floating garbage on the screen, and the goal of each level is to clear the bottom line of garbage.
== Fusion mode ==
Tetrominoes and single, distinctive "atom" blocks fall. (The ratio is not listed in the manual.)
Clearing a line containing an atom block will remove all blocks in the line except atom blocks, and it will cause a cascade on all rows of and above the atom block.
Each level L starts with L + 1 rows of floating garbage on the screen, and the goal of each level L is to connect 2*L atom blocks to the "Fusion" block initially located in one of the bottom corners of the playfield.
== Gravity ==
All game modes have identical gravity curves. The gravity is entirely determined by the player's current level. The game uses the following formula to determine the time spent per row, in seconds:
Time = (0.8-((Level-1)*0.007))(Level-1)
Though the values produced by this formula have a huge number of decimal places, the following approximate G values retain frame-accuracy and are therefore indistinguishable from the formula.
Level	Speed(unit: G)	
Speed
(unit: Seconds)
1 	0.01667 	1.00000
2 	0.021017 	0.79300
3 	0.026977 	0.61780
4 	0.035256 	0.47273
5 	0.04693 	0.35520
6 	0.06361 	0.26200
7 	0.0879 	0.18968
8 	0.1236 	0.13473
9 	0.1775 	0.09388
10 	0.2598 	0.06415
11 	0.388 	0.04298
12 	0.59 	0.02822
13 	0.92 	0.01815
14 	1.46 	0.01144
15 	2.36 	0.00706
16* 	 	0.00426
17* 	 	0.00252
18* 	 	0.00146
19* 	 	0.00082
20* 	 	0.00046
*Levels 16-20 are not included in Tetris Worlds
== External links ==
* Discussion in the forum about unlocking various hidden gameplay modes, as well as the format and editing of the "TWS" script files used in the PC version of Tetris Worlds
* Tetris Worlds Emulator
es:Tetris Worlds
Category:Games