Unfortunately the download and audio replacement didn't work so I ended up looking through the www folders for the differences between versions (excluding game content like maps or characters) and came across this
--- CiC_0.58.7_Linux/www/js/plugins/SRD_GameUpgrade.js
+++ CiC_0.59.7_Linux/www/js/plugins/SRD_GameUpgrade.js
@@ -625,7 +625,9 @@
array[i] = "img/" + url;
});
- _.isNewNWjs = Number(process.versions["node-webkit"].split(".")[1]) >= 13;
+ _.isNewNWjs =
+ process.versions["node-webkit"] >= "0.13.0" &&
+ Utils.RPGMAKER_VERSION >= "1.6.0";
The windows version doesn't use nwjs (node-webkit) so I tried reverting those lines with '+' to the line with '-' and the game was able to run! I then reverted the changes, then replaced the string "0.13.0" with "0.115.0" (the nwjs version I replaced the game with) and that ran too. It seems the problem was a string comparison instead of a number comparison because 115 > 13, but "13" > "115".
This buggy version comparison code is present throughout the file and I wouldn't be surprised if there will be future comments coming from buggy version checks. The older version of this code will break with nwjs of v1.0.0 so the plugin developer should use a proper version comparison library because it's a non-trivial piece of code to write
I'm able to play the game now. Thank you for taking the time to investigate!