Keeps Crashing

I’m running Yosemite, on a fairly new iMac. I got pretty far in the game, but it was crashing intermitently. Then, when I was half way through the game, it crashed 3 times in a row, and after the 3rd time, my saved game slot was empty.

Very dissapointing.

Ceejjj about Batman: Arkham City GOTY, v1.1