I've been doing stupid unrelated stuff for like a month now, but I've got this working again on my system. I think a lot of it needs restructuring (especially the multiple game state stuff, plus I don't use prototyping anywhere), and I especially need to put a lot of thought into the 3D/2D hybrid system which will render the UI over the game. Note that if I try to draw a 3D canvas onto a 2D one this will completely block the javascript thread until the rendering is completed, so this might be extra tricky for the picture in picture windows.
Right now I have:
Loading Screen, transitions into Select A Sim (currently covered by a city renderer which can be hidden by crashing the instance of it by edge scrolling in close zoom mode... very professionally set up) which has a few dialogs for testing, you can create and delete sims in the 3 slots, and CAS works exactly as it did in the video posted on the first page. You can't enter the game because I haven't set up the game state... All music sequencing is working correctly, and cursors would work if the city renderer didn't bug them out.
I should also probably check that the cab files are verified before permanently transitioning into the decompression stage of installation to avoid a repeat of this...