Hey, here's the troubleshooting I've gathered for Mac issues. You can see if anything here works for you!

On Mac: The application 'Game' can't be opened/ Game cannot be launched
Some things you can try:

- Hold the Control key while opening the game

- Go to 'System Preferences > Security & Privacy', and change your options to allow apps downloaded from anywhere. https://support.apple.com/en-ca/HT202491

- Download the Windows version. Download the latest version of nwjs (http://nwjs.io/downloads/). Copy and paste the nwjs files into the Windows version folder, overwriting what's inside. Run the game using the executable in the nwjs files.

- Same as above, but use nwjs 0.45.6 instead.

- Download the Windows version. Download and install Wine + WineBottler. Run the Game.exe and library files through WineBottler to produce a Game.app. Run Game.app

- Run the game using the following commands:
chmod +x Game.app/Contents/MacOS/nwjs
chmod +x Game.app/Contents/Frameworks/nwjs\ Helper.app/Contents/MacOS/nwjs\ Helper
chmod +x Game.app/Contents/Frameworks/nwjs\ Helper\ EH.app/Contents/MacOS/nwjs\ Helper\ EH
chmod +x Game.app/Contents/Frameworks/nwjs\ Helper\ NP.app/Contents/MacOS/nwjs\ Helper\ NP

Detailed chmod +x instructions:
(Thanks to Night Star for this solution!)
To fix 'Game cannot be launched', you must change two files within the "Game" files into executables.
-Right click the "Game" icon and click the option "Show Package Contents".
-Go into the "Contents" folder, then the "MacOS" folder. Look for the file "nwjs".
-Open up Terminal and type "chmod +x " making sure to add a space after x.
-Grab the "nwjs" and drag it into console. If you do it correctly, it will look like this in console:

chmod +x /Users/[user]/Desktop/Lust\ Doll\ Plus\ r17.2\ (Mac)/Game.app/Contents/MacOS/nwjs "

-Hit enter and the "nwjs" file with become an executable.

-Next, go into the "versions" folder, and then a folder with a string of numbers, something like "65.0.3325.146"
-Right click "nwjs helper" and click "show package contents"
-Go into the "contents" folder, then the "MacOS" folder, and you will see the file "nwjs helper".

-Repeat the above steps to turn this file into an exectuable, similar to what you did with the "nwjs" file.

-Hold Control when launching the game!