Same here, still waiting to see if there's any delays. I managed to get the Wallpaper Pack, before the final game was uploaded but it's gone now for some reason.
Hello, if you pre-ordered here on Itchio, you should have received an email with the download link for the mini-guide (to the address connected to your Itchio purchase). Please check your spam folder too just incase.
If you cannot find it, please send us a mail to customer.niftyvisuals(at)gmail.com ! Thank you!