Proton 10.0-1 handles the game almost perfectly except it doesn't run the videos OOTB; for that, I switched to the GE fork.

As an aside, there's an exploit that involves Alt-tabbing, really useful for the bonus content. It seems it still works for me, but not in the previous game in the series, but I'm not sure it even existed in the first game, so things may just be working normally.