That's a pretty big cock up. Bet they get heaps of negative reviews.
If you look at the forum thread for it on TA, the first thing you see in Big Bold Letters is a warning not to buy it for iPad:
http://forums.toucharcade.com/showthread.php?t=173696
Updates from the developer:
Hello (from Hello Games),
Just wanted to let you know what's going on with some folks and the iPad4.
Sorry we haven’t replied sooner, we couldn’t sleep last night ‘til we had found a fix (we have one now).
From the reports we were getting, it looks like it’s not happening on all iPad4’s, but it’s definitely happening on some. All other devices and iPads are 100% working.
If people are having this problem, I’d still love them to mail
support@hellogames.co.uk with their details (iOS version, whether they use Gamecenter, language/store region, Wifi/3G etc.). We’ll keep them up to date.
We got one report of the crash yesterday during the day (we had some more last night as the game is becoming really popular), me and Stevie (the two developers) stayed all last night until we found a fix. We fixed it very late last night, and we’ll submit that to Apple immediately after its gone through further testing here today.
Thanks for your support and patience. The toucharcade community has been amazing. Really incredible to see so many positive comments.
We’re super sorry it’s happened for some people. We want everyone to be able to play as much as they do.
Thanks,
Sean and Stevie!