Cookie Clicker is a game about clicking on a cookie to make more cookies, which can be used to purchase more advanced cookie-producing tools, like grandmothers and factories, which enables greater numbers of cookies to be produced more rapidly, which can in turn be used to buy even more powerful stuff, and so it goes on forever.
It's bad, but habit-forming: A few years ago, Phil said he had to give it up because it was a little too much like injecting heroin into his eyeball. It is the self-described "dumbest game known to mankind," yet Cookie Clicker is still clicking to this day. It's now five years old, and it just received an update to celebrate the milestone.
Cookie Clicker turns 5 ! here's a tiny update with a few upgrades and achievements; bigger and more exciting things coming soon(ish)thank you guys for all the support over the years. making these games is the best job we could ever ask forhttps://t.co/94jOHxvUED pic.twitter.com/UE0L4BiGX4August 8, 2018
Cookie Clicker is clearly an influential thing—IGN cited it as one of the driving forces behind the "idle game movement" in 2013 (which it also described as "super addictive, super dumb") and in 2016 the Daily Dot described it as the internet's "most subversive" game—but it's also a game in only the mostly loosely-defined sense. I started "playing" this afternoon, which is to say that I clicked on the cookie a bunch of times, then bought a few cookie-making things, and now it's grinding away entirely unattended in a background tab.
(I thought I was doing pretty well, grinding away 123 cookies per second. Then I placed my cursor on the "Legacy" tab and it told me I need one trillion cookies to advance to the next level. One. Trillion. Cookies.)
It could be that I'm missing some some significance as a cookie-clicking newbie; the unexpectedly in-depth Wikipedia page ascribes themes of apocalypse and capitalism to the game, which I haven't personally encountered yet. Similarly, I have no idea if the promised updates are real, or if it's just more ironic cyber-humor in the same vein as Cookie Clicker itself.
I would assume that developer Julien "Orteil" Thiennot is serious, however: The game has been updated numerous times since its release, most recently on August 1, when features including a new upgrade tier, new cookies and achievements, and a "rare type of sugar lump" were added.