以下是一个简单的俄罗斯方块游戏的C语言代码示例：

#include 
#include 
#include 
#include 

#define WIDTH 10
#define HEIGHT 20

int board[HEIGHT][WIDTH] = {0};
int currentPiece[4][4] = {0};
int currentX = 0;
int currentY = 0;

void drawBoard() {
    int i, j;
    for (i = 0; i < HEIGHT; i++) {
        for (j = 0; j < WIDTH; j++) {
            if (board[i][j] == 0) {
                printf(\" \");
            } else {
                printf(\"*\");
            }
        }
        printf(\"\
\");
    }
}

int checkCollision(int x, int y) {
    int i, j;
    for (i = 0; i < 4; i++) {
        for (j = 0; j < 4; j++) {
            if (currentPiece[i][j] != 0 && (board[y + i][x + j] != 0 || x + j < 0 || x + j >= WIDTH || y + i >= HEIGHT)) {
                return 1;
            }
        }
    }
    return 0;
}

void mergePiece() {
    int i, j;
    for (i = 0; i < 4; i++) {
        for (j = 0; j < 4; j++) {
            if (currentPiece[i][j] != 0) {
                board[currentY + i][currentX + j] = 1;
            }
        }
    }
}

void rotatePiece() {
    int tempPiece[4][4];
    int i, j;
    for (i = 0; i < 4; i++) {
        for (j = 0; j < 4; j++) {
            tempPiece[i][j] = currentPiece[i][j];
        }
    }
    for (i = 0; i < 4; i++) {
        for (j = 0; j < 4; j++) {
            currentPiece[i][j] = tempPiece[3 - j][i];
        }
    }
}

void clearLines() {
    int i, j;
    for (i = HEIGHT - 1; i >= 0; i--) {
        int lineFull = 1;
        for (j = 0; j < WIDTH; j++) {
            if (board[i][j] == 0) {
                lineFull = 0;
                break;
            }
        }
        if (lineFull) {
            int k;
            for (k = i; k > 0; k--) {
                for (j = 0; j < WIDTH; j++) {
                    board[k][j] = board[k - 1][j];
                }
            }
            for (j = 0; j < WIDTH; j++) {
                board[0][j] = 0;
            }
        }
    }
}

void generatePiece() {
    int pieces[7][4][4] = {
        {{1, 1, 1, 1}, {0, 0, 0, 0}, {0, 0, 0, 0}, {0, 0, 0, 0}},
        {{1, 1, 1, 0}, {1, 0, 0, 0}, {0, 0, 0, 0}, {0, 0, 0, 0}},
        {{1, 1, 1, 0}, {0, 0, 1, 0}, {0, 0, 0, 0}, {0, 0, 0, 0}},
        {{1, 1, 0, 0}, {1, 1, 0, 0}, {0, 0, 0, 0}, {0, 0, 0, 0}},
        {{1, 1, 0, 0}, {0, 1, 1, 0}, {0, 0, 0, 0}, {0, 0, 0, 0}},
        {{0, 1, 1, 0}, {1, 1, 0, 0}, {0, 0, 0, 0}, {0, 0, 0, 0}},
        {{1, 1, 0, 0}, {1, 1, 0, 0}, {0, 0, 0, 0}, {0, 0, 0, 0}}
    };
    int randomPiece = rand() % 7;
    int i, j;
    for (i = 0; i < 4; i++) {
        for (j = 0; j < 4; j++) {
            currentPiece[i][j] = pieces[randomPiece][i][j];
        }
    }
    currentX = WIDTH / 2 - 2;
    currentY = 0;
}

int main() {
    int gameOver = 0;
    int key;
    srand(time(NULL));
    generatePiece();
    while (!gameOver) {
        system(\"cls\");
        drawBoard();
        if (checkCollision(currentX, currentY + 1)) {
            mergePiece();
            clearLines();
            generatePiece();
            if (checkCollision(currentX, currentY)) {
                gameOver = 1;
            }
        } else {
            currentY++;
        }
        if (_kbhit()) {
            key = _getch();
            switch (key) {
                case 'a':
                    if (!checkCollision(currentX - 1, currentY)) {
                        currentX--;
                    }
                    break;
                case 'd':
                    if (!checkCollision(currentX + 1, currentY)) {
                        currentX++;
                    }
                    break;
                case 's':
                    if (!checkCollision(currentX, currentY + 1)) {
                        currentY++;
                    }
                    break;
                case 'w':
                    rotatePiece();
                    if (checkCollision(currentX, currentY)) {
                        rotatePiece();
                        rotatePiece();
                        rotatePiece();
                    }
                    break;
                case 'q':
                    gameOver = 1;
                    break;
            }
        }
        Sleep(100);
    }
    system(\"cls\");
    printf(\"Game Over!\
\");
    return 0;
}

这个代码使用了Windows的conio.h和windows.h库来实现控制台界面和键盘输入。你可以在Windows环境下编译和运行这个代码。