1. The game starts with an empty grid and a single, random Tetrimino (a geometric shape composed of four square blocks) falling from the top of the grid.

2. Use the arrow keys to move and rotate the Tetrimino to fit it into an empty space at the bottom of the grid.

3. Once the Tetrimino lands, it becomes fixed in place, and a new Tetrimino begins to fall.

4. As the game progresses, the Tetriminos fall faster, making it more challenging to fit them into the available spaces.

5. When a horizontal line is completely filled with blocks with no gaps, it clears from the grid, and any blocks above it drop down to fill the space.

Scoring:

• You score points by clearing lines and the more lines you clear at once, the more points you earn.

• As you progress through the game, the level increases, and the blocks fall at a faster rate.

Game Over: The game ends when the stack of Tetriminos reaches the top of the grid and no new Tetrimino can enter the play area.

These are the basic instructions for playing Tetris. Enjoy the game!