This was fun, but I had to modify the game files to be able to get through the final battle. (Fortunately, it's all technically human-readable!) Details below in case people want to avoid a small spoiler, but the gist is that the game stopped taking my inputs during that fight.
Of course, this does fit the theme of trying to thwart the player, but I don't think Rea should be fighting us that hard. :)
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I think the calls to `window.moveTo` were taking more than a frame to complete on my computer and so the keys were never being polled, or something like that. It just stopped responding to my inputs as soon as the window started to move. I simply removed those calls in the JSON files and was able to finish. If you only called that function once every two frames, that should also fix the issue.