Yeah, the game was running directly from Steam. After some messing around I'm thinking that what caused that to happen was that I had updated node-webkit to 0.11, and tested it working just fine on Windows without testing if it was working OK with OSX.
Unfortunately after rolling back all the changes (greenworks plugin to 10.5 and node-webkit to 10.5), the game still works fine on Windows, but on OSX it just closes itself after opening up, without any errors. I'd love to see some errors so I can look around...
I searched a bit and found posts about having to chmod the file so it would get the permissions back, but that didn't seem to work. I'm wondering, what version of Node-Webkit/Greenworks plugin are you using, and does it work just fine for all the exports (Linux and OSX)?
Thanks once again for the help!
edit: after some searching around, I tried running the game from the terminal to see if it would specify the error.
It says "dyld: lazy symbol binding failed: Symbol not found" and says it's referenced from greenworks-osx32.node. I honestly have no idea what this could mean. ):
edit2: and now the weirdest thing - I removed the greenworks plugin just to see if the game would run OK without it, but it doesn't. If I open it, the loading percentage gets stuck and red. I tried once again running the terminal to see what was the error, and apparently each line there's an error about not being able to load the images.
The error starts with "Warning: shared memory creation failed; out of file descriptors" repeated over and over, then it proceeds to try and load the images giving out an error for each one. My guess is that something in the new versions of Construct is clashing with the old Node-Webkit, but I don't even know if that is possible... I honestly wish I could just update everything and it would work but I don't think there's a greenworks plugin for the latest version of nw.js (the one that got rid of the hiccups), right? Maybe I could just apologize to OSX users and turn off the achievements for the time being...