We are aware of this issue. Unfortunately we have stopped work on Steambirds: Survival and will probably not be able to address this issue. (Our best guess is that, some time after we stopped work on Steambirds: Survival, an iOS update changed something that the Options menu needed and thus the game now crashes when the Options button is clicked.)
We are very sorry about this. Fortunately, to our knowledge the rest of the game is working as well as it always has.