Part 3 of this guide from Emanuele Feronato: "Here we are with the third step of Perfect Square! HTML5 prototype made with Phaser.
In first step the basics of the game have been built with only 100 lines of code.
In second step we added levels, and now we have new improvements such as a brief “how to play” section, saving player progression using localStorage and scaling the game to fill any kind of device and resolution."