Rotate each falling voxel block before it reaches the slot, or discard it when its shape cannot match the cutout at all. Your run is measured only by survival time and the number of blocks that successfully pass through. Use Left/A or the left side to rotate counterclockwise, Right/D or the right side to rotate clockwise, and Down/S/Shift, an upward swipe, or DROP to discard. The fall speed ramps up as the run goes deeper.