Oh yes, I have had to put that at the top of the description on iTunes. The game will only work with devices equipped with 512 of Ram. I'm guessing HTML5 is very Ram hungry. It was working on 3gs and older iPod touches before the backgrounds were added in, but I couldn't find a way to optimize the game enough to run with them.
I did request to Ludei about a Ram tracker in CocoonJS Launcher but they glossed over it. Still, I hope they take it on board in the future.
So unfortunately this game will only work on iPhone 4 and above, and iPod 5th gen.