> Note to the author: the illusion would be even better if you used the user-agent to render a system-accurate mouse cursor ;) (on macOS the real cursor is black and the fake one is white)
I've already seen sites that change the cursor's appearance, so I wasn't particularly "shocked" by that (I'm on a Mac).
However, what should improve the illusion would be to not move the cursor outside of the view area.
It's a bit odd to me that it doesn't ask for any kind of permission on Chrome, just that a user click initiates it. It does briefly pop a hint that "<esc>" will release the mouse.
I've already seen sites that change the cursor's appearance, so I wasn't particularly "shocked" by that (I'm on a Mac).
However, what should improve the illusion would be to not move the cursor outside of the view area.