Well after a bit of looking around, I figured it out. Hope this helps.
Creating an app for mac.
1. Export your game. (ex. game)
2. Create a directory with the same name as your app, with the extension .app. (ex. game.app)
3. Right click it and press Show Package Contents.
4. Create a directory inside named Contents.
5. Create a directory inside Contents named MacOS.
6. Add the Info.plist file into the Contents directory (found here
http://sourceforge.net/apps/trac/game-editor/browser/trunk/Info.plist).
7. Lastly put the exported game into the MacOS directory.
Now you should be able to double click the .app to run it. Strangely I still have the problem where I have to move the game window for it to start updating the view. Seems to be some bug, but at least now it comes up when I click it, instead of hanging like you explained.
Haven't yet learned how to do icons, as I believe that is handled by an Info.plist file, but my first few attempts have not worked. Will continue looking into it.
-Edit
I have found a way to change the icon, but it isn't quite as simple as akr says, so I think this is a harder way of doing it, but the only one that I've found.
You need to convert your icon file to a format supported by the preview section of the files get info. I've seen reference to the extension rcrs, which didn't work for me. Anyway, I used this site to do it.
http://iconverticons.com/I had to click options at the bottom, and click finder-compatible icons to get a file that would work. After clicking convert it will give you several files to download, but the one that worked for me was the hqx (the finder-compatible one). I extracted the file and did the following.
1. Right click and select Get Info.
2. Click the icon at the top left of the info window, and press command c.
3. Right click your .app directory and select Get Info.
4. Click the icon at the top left of the info window and press command v.
That should have copied the icon you created into the app.
akr, if there is an easier/more direct way to do this, I would love to know.