Being a 32 bit game is not an issue. 64 bit systems support 32 bit software, the only issue is the other way around a 32 bit system does not support 64 bit programs.

With that said although Myst IV is updated to run on newer systems and does work for many Mac users, some Mac users are having issues with the game working that Cyan is expected to release an update to address at some point, although it is taking a while for the update to come out. Since you already own Myst IV, I suggest going ahead and installing it and seeing if works or not, if does not work you can always uninstall it.

Thanks! Sadly I've tried downloading it and running it twice now. All it does is the "bouncing icon" trying to load thing. Didn't know if anyone else has had a similar experience and found a solution.

Oh and actually after a few tries I also get a pop up message saying the "game quit unexpectedly".

Try to execute the launch script manually. Open up the Myst IV folder in your steam folder on your computer, and you'll see the Myst IV Revelation application. You have to right/control click on the application, then select "Show Package Contents". Then open the Contents folder, and the MacOS folder. Inside that you will find the launch script. Run/Open that and see if it launches correctly.

Hmmm. Ok I found "contents" and then "MacOS" and then a plain text file marked as "run.sh" that just opens in notes. It says "#!/bin/bash
# autogenerated file - do not edit

open steam://run/925940

Now what?

That was not the correct file, it would the same as other files you would use for running applications, difference being that you are opening it from within the steam file directly. From what Halloween Jack is saying it though sounds like the instructions I gave you were for Mac versions before the one you have now, so it is not likely to work then, but would not hurt to try. I think you will likely have to wait until Cyan releases an update though.

Thanks, all. I guess I am just going to have to wait until Cyan implements the appropriate updates.

@mithrandir5282, did you try running in CrossOver[www.codeweavers.com]?

On my 2019 MacBook (which shipped with Catalina) I created a new APFS volume and installed Mojave on it. I can run Myst IV on it with no problem. It also works for "URU: Complete Chronicles".