Having an extremely frustrating time here as well. Game often hangs and eventually crashes at loading screens - about halfway into Episode 2 and it's already happened over 10 times (which is unacceptable IMO).
Basic specs of my machine:
MacBook Pro: 15-inch, Mid 2012 (Retina)
Processor: 2.6 GHz Intel Core i7
Memory: 8GB 1600MHz DDR3
Graphics: Intel HD Graphics 4000 512 MB + NVIDIA GeForce GT 650M 1024 MB
Software: OS X 10.8.2 (12C3012)
Game Settings all at max (HIGH or ON) save for resolution, which I've got at 1024 x 768.
Any suggestions for how I can stop this from happening?