On 10.10.5, the latest retina-patched pre-compiled app does launch and display the File Open dialog, but nothing happens when you select a game file to open. Running the Gargoyle binary inside the .app package in Terminal gives this:
$ ./Gargoyle
dyld: lazy symbol binding failed: Symbol not found: _AudioUnitInitialize
Referenced from: /Users/USER/Desktop/Gargoyle with retina patch try 2.app/Contents/PlugIns/../Frameworks/libSDL-1.2.0.dylib (which was built for Mac OS X 10.11)
Expected in: /System/Library/Frameworks/AudioToolbox.framework/Versions/A/AudioToolbox
dyld: Symbol not found: _AudioUnitInitialize
Referenced from: /Users/USER/Desktop/Gargoyle with retina patch try 2.app/Contents/PlugIns/../Frameworks/libSDL-1.2.0.dylib (which was built for Mac OS X 10.11)
Expected in: /System/Library/Frameworks/AudioToolbox.framework/Versions/A/AudioToolbox