Ah geez, that link isn't opening for us anymore either! Those were really good and clear instructions... I found these instructions here https://bazilisk.itch.io/elevate which should be the same but let us know whether they work for you!
[
- Press CMD + Space, type Terminal and press Return
- Type cd Downloads/ and press Return
- Type xattr -d com.apple.quarantine "Tomorrow Will Be Dying.app" and press Return
The above will remove the game from quarantine and you will be able to run it. If you moved the file into other directory, please change Downloads/ from second step to the appropriate location.
]
Sorry it took too long, it took me a while to get to my old Mac to verify the above steps worked for me as well. (Btw, the quotations around the app name are important because of the spaces in the name).
Hope that helps!