Yo. Me here.
I used the code for the Codidactyl on the run as basis for the game, added a wrapper checking for the Konami-code by being a simple finite automaton and after that creating the canvas and loading the game. Then I made changes to the game code to support the new game type (fly instead of jump, sugar comes from both reactions at random heights).
The game uses HTML5
<canvas> and runs a few async main loops (codidactylHandle for the Codidactyl, lollipopHandle for the objects, collisionHandle for checking for collisions and drawloop for erasing and redrawing the images). Furthermore, there has been an event-based jumpHandler, which reacts to the click/keydown event.
You can find the game source code in this GitHub Gist, which I also used to share it with the other team members a few days before April 1st (which was also the first time they heard of it): https://gist.github.com/luap42/4d788dffd602801492c536fce58129b3
The code has been obfuscated with https://obfuscator.io/, using the settings that seemed to be the most obfuscating to me.
Feel free to ask in the comments if you have any further questions.