The New Tetris

The game differs from the original Tetris in several ways. Firstly, you can not only clear lines, but also form 4x4 squares of four pieces to create blocks. When a block is formed, it turns gold or silver, depending on the nature of the block. Blocks can only be formed from whole stones: If part of a stone has been cleared, it cannot be used to form a block. If a row containing parts of a block is cleared, it receives more points.