The conveyor belts have 3 speeds: use the left and right arrows, or use your mouse to click the toolbar settings at the bottom of the screen, to control the direction and speed of the conveyor belt. Get all of the boxes into the bin to complete the level. If a box doesn't make it to the bin, it will be placed on the conveyor belt for you to try again. You'll earn a time bonus for being fast, or will fail the level for being too slow—so keep an eye on the timer!