• Official Cookie Clicker : http://orteil.dashnet.org/cookieclicker/
• CERN Particle Clicker: https://particle-clicker.web.cern.ch/particle-clicker/

Make a basic structure with HTML / CSS / JS. In the HTML, make a button named « Click » with an identifier and a div with an identifier output and set his initial value to 0.

Set up variables at the head of your JS that will allow us to manipulate our button and our div. We'll need another variable score initialized at 0.

When we click on the button, increase the value of the variable score by 1, then display that score in the output div.

Add a button with an identifier multiply. Create another click counter (name the variable multiplier and set it to 1) on that button. Create an associated function to the multiplier click called increaseMultiplier.

Make it so the score of the first button click doesn't increase by 1 but by the multiplier value. For example, if i clicked once on the multiplier button, each click on the first button will increase the score by 2 instead of 1.

The multipier allows you to raise the score more quickly. It shouldn't be free ! Try to decrease the score by 50 when you click on the multiplier button.

We can't go in debt and the score can't get below 0. Try to update the score output after the multiplier purchase.

Display the multiplier counter inside the button. For example, if the counter is at 5, the button text should be « Multiplier x5 ».

Buying a lot of multipliers is too easy. After buying six multipliers you'll figure out why the price should increase with each multiplier bought. For example, the first should be worth 50, the next 100, 200, and so on... Make it simple, you don't need a lot of conditions. Find a good way to raise the price !

In the button text, in addition to « x5 », add the cost of the next purchase.

New upgrade to buy: Autoclick. As soon as you hit 200 score, a click is made automatically each second. (setInterval is your friend)

Autoclicked won't be automatic anymore. From now on you'll need to buy the autoclicker. Add a button with an autoclick identifier. It'll cost 500. Once the autoclicker bought, the button will have to be disabled.

From now on, we have to be able to buy a bonus that increase the score on each click by 200% for 30 seconds. It means that if you're supposed to get 3 on a click, for next 30 seconds the bonus will increase that click value to 6. After the 30 seconds the score should increase by 3 again. Create the « BONUS » button with an identifier bonus, and set the cost at 5000. Once the bonus bought, the number of seconds will be displayed in the button with the count and the button will have to be desactivated while the bonus is active. Once the bonus is over, the button have to be reactivated with the same text as before pressing it.

Make it so the buttons multiplier, autoclick and bonus can't be clicked UNLESS you have enough score to buy them.

Make it pretty ! No pictures !