Kingdom rush crashing

[Brainy142]

I'm on the first snow level, and the game keeps crashing during the boss fight.

Any ideas on how I can prevent the crashing? I've tried closing apps, rebooting, disabling unnecessary features (both in game and on the ipod itself), disabling network access, (I found if I got any notification while playing the game it will crash).

Thanks,
Brandon W.

ps. The game is updated to the latest version
pps. I am running the game on an ipod touch 4th generation.