DUDE! FIRST OF ALL I LOVE YOU SO MUCH! I had a sudden and vivid memory of this game that led me to find your post and I'm about to relive 2012.
I downloaded this onto my old iPod Touch running iOS 9.3 or whatever (5th Gen) since my new iPhone 8+ would not download it, with being 64-bit and iOS 11 and all.
Also quoting your post, the dude who had the iFunBox error:
I got the exact same one. No idea why but I found a workaround. What I did was use iExplorer instead and I've opened up the game to see all the episodes loaded onto the list! Haven't tried playing them yet though. I know it's been a year but hope you see this and be able to play as well if you haven't found a fix already.
Image proof: sorry about the quality and orientation lol idk how to fix it.