Hi,
I downloaded the demo version of your program and checked it out; seems to be a pretty nice game.
I'm a long-time Mac developer (back to the days of System 7, in fact), so I'm all too familiar with the headaches you encounter when moving existing code to a new version of Xcode, switching to ARC, and so forth. I'm assuming you used the automatic Xcode migration process to switch from garbage collection to ARC?
I'd propose to tackle this problem by running the updated code under the debugger to pinpoint the cause of the hang. Might also be necessary to run with Instruments to check for memory management issues, leaks, and so forth.
Please get in touch if I can answer any questions
- david