Make a game like Lumines with Flash

// declaring some setup variables
// number of horizontal cells
grid_width = 16;
// number of vertical cells
grid_height = 10;
// size of the cell
tile_size = 30;
// offset in pixels fron the left side of the stage
x_offset = 10;
// offset in pixels from the top side of the stage
y_offset = 10;
// number of different colors that can be displayed in a brick
different_colors = 3;
// boolean values saying if I should wait for the left (or right, up...) key to be released
// this is used to make the player move bricks tapping arrow keys instead of just pressing them
wait_left = false;
wait_right = false;
wait_up = false;
wait_down = false;
// array containing the game field data
field = new Array();
// array containing the bricks I can move
moveable_bricks = new Array();
// initializing and drawing the play field
for (x=0; x<grid_width; x++) {
	field[x] = Array();
	for (y=0; y<grid_height; y++) {
		field[x][y] = 0;
		// look how I determine cells position according to tile size and offsets
		cell = _root.attachMovie("brick", "brick_"+_root.getNextHighestDepth(), _root.getNextHighestDepth(), {_x:x*tile_size+x_offset, _y:(y+2)*tile_size+y_offset});
		// first frame = empty cell
		cell.gotoAndStop(1);
	}
}
// placing the four bricks
for (x=0; x<4; x++) {
	// again, look how I determine bricks position according to tile size and offsets
	brk = _root.attachMovie("brick", "brick_"+_root.getNextHighestDepth(), _root.getNextHighestDepth(), {_x:(grid_width/2+(x%2))*tile_size+x_offset, _y:y_offset+tile_size*Math.floor(x/2)});
	// setting a random color for the brick (frames 2 to different_colors+1)
	brk.gotoAndStop(Math.floor(Math.random()*different_colors)+2);
	// saving brick position
	// 0: up left
	// 1: up right
	// 2: bottom left
	// 3: bottom right
	brk.pos = x;
	// saving the depth of the brick into the moveable_bricks array
	// if you look how did I assign brick names, you'll see that I can determine a brick name
	// starting from its depth. It's simply "brick_"+<the_depth>
	moveable_bricks[x] = brk.getDepth();
}
// main function, to be executed at every frame
_root.onEnterFrame = function() {
	// this is how I detect if a key was tapped:
	// when it's pressed, I wait for it to be released (in this case: not pressed)
	// thanks to the wait_<direction> variable
	if (Key.isDown(Key.LEFT)) {
		wait_left = true;
	} else {
		if (wait_left) {
			// if the left key has been tapped, move the four bricks on the left
			for (x=0; x<4; x++) {
				// this "if" is used to determine if the bricks are still inside the game field
				if ((_root["brick_"+moveable_bricks[x]]._x-x_offset)/tile_size-_root["brick_"+moveable_bricks[x]].pos%2>0) {
					_root["brick_"+moveable_bricks[x]]._x -= tile_size;
				}
			}
			// reset variable, now I must wait again for a key to be pressed
			wait_left = false;
		}
	}
	// same routine for the right key
	if (Key.isDown(Key.RIGHT)) {
		wait_right = true;
	} else {
		if (wait_right) {
			for (x=0; x<=3; x++) {
				if ((_root["brick_"+moveable_bricks[x]]._x-x_offset)/tile_size-_root["brick_"+moveable_bricks[x]].pos%2<14) {
					_root["brick_"+moveable_bricks[x]]._x += tile_size;
				}
			}
			wait_right = false;
		}
	}
	// when the DOWN arrow is pressed, I must rotate the bricks clockwise
	// block 0: moves to the right and becomes block 1
	// block 1: moves down and becomes block 3
	// block 2: moves up and becomes block 0
	// block 3: moves to the left and becomes block 2
	if (Key.isDown(Key.DOWN)) {
		wait_down = true;
	} else {
		if (wait_down) {
			for (x=0; x<4; x++) {
				switch (_root["brick_"+moveable_bricks[x]].pos) {
				case 0 :
					_root["brick_"+moveable_bricks[x]].pos = 1;
					_root["brick_"+moveable_bricks[x]]._x += tile_size;
					break;
				case 1 :
					_root["brick_"+moveable_bricks[x]].pos = 3;
					_root["brick_"+moveable_bricks[x]]._y += tile_size;
					break;
				case 2 :
					_root["brick_"+moveable_bricks[x]].pos = 0;
					_root["brick_"+moveable_bricks[x]]._y -= tile_size;
					break;
				case 3 :
					_root["brick_"+moveable_bricks[x]].pos = 2;
					_root["brick_"+moveable_bricks[x]]._x -= tile_size;
					break;
				}
			}
			wait_down = false;
		}
	}
	// when the UP arrow is pressed, I must rotate the bricks counter-clockwise
	// block 0: moves down the right and becomes block 2
	// block 1: moves to the left and becomes block 0
	// block 2: moves to the right and becomes block 3
	// block 3: moves up and becomes block 1
	if (Key.isDown(Key.UP)) {
		wait_up = true;
	} else {
		if (wait_up) {
			for (x=0; x<4; x++) {
				switch (_root["brick_"+moveable_bricks[x]].pos) {
				case 0 :
					_root["brick_"+moveable_bricks[x]].pos = 2;
					_root["brick_"+moveable_bricks[x]]._y += tile_size;
					break;
				case 1 :
					_root["brick_"+moveable_bricks[x]].pos = 0;
					_root["brick_"+moveable_bricks[x]]._x -= tile_size;
					break;
				case 2 :
					_root["brick_"+moveable_bricks[x]].pos = 3;
					_root["brick_"+moveable_bricks[x]]._x += tile_size;
					break;
				case 3 :
					_root["brick_"+moveable_bricks[x]].pos = 1;
					_root["brick_"+moveable_bricks[x]]._y -= tile_size;
					break;
				}
			}
			wait_up = false;
		}
	}
};