Tommy Leung from Ourcade presents a new tutorial: "Creating a spotlight or flashlight effect in Phaser 3 is fairly simple once you know how to use alpha masks.
You can also use this technique for a “magic lens” effect or anything that involves revealing hidden information.
If you are not familiar with using alpha masks in Phaser 3 then check out this first.
In this article, we will be building on the code example from our Reveal Effect in Phaser 3 with Alpha Masks to create a flashlight effect that illuminates a darkened Phaser logo."