I want to create a space within the service and am considering the js libraries.
Ideally, I would like to use UE (Unreal Engine), but I'm thinking that it would not be the first choice considering the devices that are compatible with it (just when I was thinking about it, "UE for Fortnite" came out, so I'm wondering if I should swing away from it...).

js libraries

The following content is generated content (some additions and corrections have been made)

Several JavaScript libraries are recommended for creating 2D metaverse spaces on the web. Below are some of the main libraries.

p5.js ( https://p5js.org/ ):
p5.js is a JavaScript version of a creative coding language called Processing, which makes it easy to implement 2D graphics and interactions. It is well-documented, easy to understand for beginners, and suitable for creating interactive metaverse spaces.

Phaser ( https://phaser.io/ ):
Phaser is an HTML5 2D game framework and library suitable for moving 2D icons around the web. It offers a powerful physics engine, sprite animation, tile maps, and many other features to create advanced metaverse spaces.

PixiJS ( https://www.pixijs.com/ ):
PixiJS is a high-performance 2D WebGL rendering engine that makes it easy to implement clean graphics. With numerous plug-ins and extensibility, it is suitable for developing in the metaverse space, as it allows for advanced interactions and animations.

Three.js ( https://threejs.org/ ):
Three.js is a 3D graphics library, but it can also be used to create 2D metaverse spaces. 2D metaverse spaces can be created by setting the camera to OrthographicCamera and restricting 3D objects to 2D representations. This allows for a 2D metaverse space to be realized.