Cookie Clicker

Cookie Clicker is an endless game where the entire point is to gather cookies, then use them to buy items and upgrades which do nothing but gather cookies even faster.

Initially, the player can gather cookies by clicking on the giant cookie visible on the screen. The cookies can be spent on things like automatic cursors (that do the clicking for you), grandmas (that bake cookies), farms (where cookies are grown), time machines (which bring cookies back from the past) and others; these purchased items can in turn be upgraded to boost their cookie production rate. The price of the items and upgrades keeps rising as you purchase more of them. The game runs on its own even when not attended to, so generally the gameplay consists of letting the game run in the background and occasionally checking back to buy some more upgrades.