Tetris Payout

Tetris Payout is a Tetris game which you can win money if you are lucky. As of 2013, the game is undumped and little is known about the actual gameplay.

Gameplay

 * The game is Ultra mode styled. The goal of this game is score as many points as possible in given time limit. The time limit is shown as a green horizontal bar. The game session lasts about 2 minutes in this video, but it might be variable based on the machine's DIP switches, remaining coins, and/or other factors.
 * The game offers two options: "Practice" mode where you play the game without payout, and "Skill with prizes" mode where you can win money based on your score.
 * This game featrues 11 piece previews, but it's often taped over in most countries, leaving the player with 0 previews. Seeing the taped-over condition, the number of preview is most likely not-configurable via machine's DIP switches.
 * Playfield appears to 10w x 18h. However, the top out condition is not known, so maximum allowed height is unknown.

Scoring
Scoring appears to be based on the height the line(s) got cleared. No points are gained from soft drop.

The following table is from the gameplay video: A different scoring table is shown in "How to play" screen, so the scoring may vary depending on the game versions or DIP switches.

It's currently unknown how much points are awarded from 11+ height clears or multiple line clears.

Rotation system
The following diagrams for the JLT piece orientations have their left-most orientation as their initial orientation, and clockwise rotations are applied going to the right.

For the J, L, and T pieces, the piece rotates around its center.

The O piece has a single rotation state.

S, Z, and I are "2-state", but these pieces exhibit a special property: Counterclockwise rotations from the vertical state will bias the piece to the left, and from the horizontal state will bias the piece to the right. The opposite is true of clockwise rotations: rotation from the vertical state will bias the piece to the right, and from the horizontal state will bias the piece to the left.

So this S piece:

Could rotate to either of these states:

Same goes for the Z and I pieces.

This Z piece:

Rotates to either:

This I piece:

Rotates to either:

When using only counterclockwise or only clockwise rotations with these pieces, nothing special occurs. However, alternate presses of these rotation buttons will add up the opposite biases and cause the piece to drift. For example:

The I-piece is rotated clockwise, and then counterclockwise. The piece is biased to the right, and then again, which causes the piece to end up one cell to the right of where it was originally.