Laura Sammons has shared the source code for a wonderful 2D platformer game. In the game, your job is to collect coins while avoiding all of the poison bottles on the platforms. Once you do, you just need to collect the badge to win the game!
You can play the game here.
From the article: "Phaser.io is a javascript-based desktop and mobile HTML5 game framework. Based on a game template and a simple tutorial, I created this game in 2018 learning how to implement this gaming library and program some simple game physics."