Could this be able to run on Windows XP?
I haven't used Windows XP for years now, and I'm no longer sure what can run on WinXP, but if you have a web browser that supports moderately recent CSS (variables, flexbox, grid) and Javascript (local storage, speech API), that browser should be able to run a game made with this engine ( but I expect some of the CSS may need changes to be more compatible).
In 2022 only around 0.1% of all devices run winxp, that's a very small niche and I think that for anything other than retro gaming people should really switch to something else. I have currently no plans of making the engine more compatible for windows xp than it already is.
I do not use Windows XP. But read this: Although I don't know many people I do know some who use Windows XP. Most of them with a laptop. Some of them also play computer games. I myself use a 32bit Linux system and play Windows games using Wine 1.6.2-20 which can at most simulate Windows XP. And that's quite enough! So that you understand me correctly: I am a power gamer! I have more than 300 games on GOG that work perfectly for me. I don't let anyone tell me when I should start using a newer operating system. And I laugh at individuals who think they know how many computer users use 32 bit systems. And I give all computer software developers a fair chance to develop software that could also be of interest to OURSELVES ;-)