Click the Evil Cat to defeat an Evil Cat. If you defeat 50 Evil Cats in quick succession, the combo will change by 1, until you reach x5 combo. Weapons defeat Evil Cats for you. To buy a weapon, you must have defeated enough Evil Cats to buy it. If you have enough Evil Cats to buy a weapon, click the shop button and type in the number of the item you want to buy.
Still based on Gobo World by @rex5554 :) The original version of this also by him I just made it so you can see how many you are getting per second (and made changes to the Evil Cat speed)