I'd recommend you collect the art and sounds you think you will need from iStock photo ahead of time and I'd push you to leave room for some ads in the app to give yourself an idea of what putting together a complete app that can generate some sandwich money takes. (Or figure out what you could sell via in app purchase) Make it universal if you can as well - anything to get it in more categories on the store. Also go look at existing games that do well to see what they are doing well and poorly. Writing the code is only part of publishing apps and Id say probably not the most important part.
Also, for fun google "Tick Tack Toe in lisp" I found these to be neat little programs to read though not especially relevant to the production of the game :)
Learning objective-c shouldn't be difficult as I have some (though quite dated) experience with c/c++ (as well as java, javascript, ruby, python).
resources i am considering:
http://pragprog.com/book/carubym/rubymotion
http://www.bignerdranch.com/book/ios_programming_the_big_ner...
https://itunes.apple.com/us/book/ipad-iphone-app-development...
Is Apple likely to approve your app as long as it works like its supposed to?
You'll need to register to see the guidelines: https://developer.apple.com/appstore/resources/approval/guid...
Also, put in now for the apple developer account, that could take weeks to get approved to publish on the app store.
And, during the holidays the app store shuts down for approving apps.