In Godot, there was just an option for web build. The only curious thing I had to google to fix, is apparently you have to name your game html file "index" when you export it. Then zip, upload, and tick the little box saying "playable online" or whatever it was.
The minimalism was partly to emphasise the "exposed" nature of being "out in the open" ... but also influenced by my lack of modelling skills (having a main character be a giant sphere also helped here!).
Shoebox is right! The square platforms are actually setup to be added infinitely, I was just going to let the player request a new one to be added by interacting with any wall... but then it would've made hiding from the eye easy coz you could've just run really far in a straight line, not particularly interesting. Then I never got around to adding the hiding part in either. 🤷