After you are done playing your first game in the Secret Supply Event, you will be able to see some Shop Items above the Green Button which can be used to increase your points in various ways. For example, the gear power-up can increase your multiplier once activated. The multiplier is the "1x" number that appears near the top of the screen and it works in the following way: if your multiplier number is raised to 4, any points you get from the machine will be multiplied by 4 and added to your total, so using this power-up is a great way to get more points.