Any idea how to fix the quarantine issue, if that indeed is the case? As for the problem with executables, I assume it's the usual 'chmod +x' thing. Never seems to work for these nwjs games, at least whenever I've tried.
I don't know how familiar you are with the Terminal. The following instructions are writen for people who are not.
To check quarantine, start Terminal and type "xattr " without the quotes at the prompt and drag the
nwjs app into the Terminal window. Terminal will fill out the path for you. Mind there is a space between the command and said path. Hit enter. If you see
com.apple.quarantine in the results, the app is quarantined.
To remove the quarantine, type "xattr -d com.apple.quarantine " and drag the app again into the window. Hit enter. Quarantine should now be removed.
To check whether the executable misses the execute permission, check the properties of the file in /Contents/MacOS. If it's kind is Unix executable, or in other words, Terminal starts when you open that file, then the permission is ok.
If it's anything else, it has lost its execute permission.
To fix this, start Terminal and type "chmod a+x " without the quotes at the prompt and drag the file inside the Terminal window. Terminal will fill out the path for you. Again mind there is a space between the command and the path. Hit enter. The file should now be executable.
As a general precaution, make a duplicate of the app first before changing its attributes or permissions.