Tetris (Mega Drive)

Tetris for Sega Mega Drive/Genesis, an adaption of 1988 arcade game, went unreleased due to various licensing issues.

Game modes

 * Normal: Marathon mode
 * Time Trial: A three minute countdown
 * Doubles: Two-player co-op

Gameplay details

 * ARE without a line clear: 41 frames
 * Line clear delay: 17 frames
 * ARE after a line clear: 24 frames
 * Lock delay is either 12 or 19 frames, selected seemingly random
 * DAS: 6 frames initial, 6 frames auto repeat
 * Hard Drop is 1G and disables all controls of the piece until it locks. There is no special bonus for this move. Both soft and hard drops of an I Tetromino at the beginning of level 0 give the player 40 points.
 * The level increases for every 10 lines for levels 0-9, and 20 lines for levels 10-14 and is capped at level 15. There seems no level timer mechanics.
 * Doubles mode has 2x2 invisible wall at the top-center of the playfield, presumably to prevent a player's active piece to overlap with the other player's newly spawned pieces.

Scoring
Scoring in this game is very different from the arcade original, encouraging players to place their pieces on high places.

For every piece the player places, with or without lines, the game awards the points using this equation:

Score = (Level*3) + (Lowest row*2) + (Manual drop rows*2) + (Line clear bonus)


 * (Level*3) is awarded for every piece except in level 0. This is the only bonus where the level number matters.
 * Lowest row is the minimum Y position the piece landed. The minimum is 1 when the piece is directly placed on the floor. The maximum is 20 when the player places a horizontal I Tetromino on the 20th row.
 * Manual drop rows is the number of rows passed with a soft or a hard drop. The maximum is 19 when dropping a horizontal I Tetromino to the floor. Note that this bonus is awarded only when the player manually cancels a lock delay. Letting a piece lock by itself will set this bonus to 0.
 * Line clear bonus follows the following table. Note that it doesn't increase with levels.


 * Examples:
 * The minimum score for each piece is 2, awarded when the player do absolutely nothing for the first piece on level 0.
 * Score = (0*3) + (1*2) + (0*2) + (0) = 2
 * When the player uses hard drop for an I Tetromino at the beginning of the level 0, the player receives 40 points, 2 for placing the piece to the floor and 38 for dropping a piece for 19 rows.
 * Score = (0*3) + (1*2) + (19*2) + (0) = 40

Items
This game has an items option. When enabled, a flashing Tetromino will appear for every 10 pieces. When at least one line is cleared with the flashing Tetromino, the item will activate its effect. Excluding the S Tetromino, when these flashing Tetrominos are placed without clearing lines, they will stop flashing, and the item disappears. The item effects are specific to each Tetromino:
 * I: Activates a random effect from other Tetrominos.
 * O: Larger line clear bonus.
 * Z: A slightly larger line clear bonus.
 * T: Erase nearby three lines.
 * J: Increases the level by one.
 * L: Reduce the level by one.
 * S: This item does not disappear when placed, and do different things depending on whether the S Tetromino was "activated" by immediately clearing lines like other items, or when "placed" on the field without clearing lines.
 * Placed: It will continue flashing in the field and will disappear after 10 seconds. There seems no special effects when "placed" S blocks are cleared before disappearing.
 * Activated: The whole S Tetromino disappears when the lines are cleared, in addition to the blocks included in the lines.

Easter egg

 * Hold Down + C + Start at the Sega screen to display "PROGRAMED BY NAOKI OKABE" at the bottom of the title screen. Typical bootleg copies of this game (with glitched Sega screen and altered copyright strings) retain this feature, with the programmer's name intact.
 * Pause the game and push A, B, or C button to display the maximum lines record of the current game mode. It is only stored on the RAM and will be erased when the console is turned off much like the high score.