My honest view on this:
Rayman Classic on iOS definitely one of the worst ports Ubisoft did with any Rayman game. Some people out there criticise Rayman Adventures but no. Let me tell you people, this is the thing that deserves criticism and not Rayman Adventures. First of all, making it iOS exclusive is the dumbest decission ever. Ubisoft should learn from Sega when they remade Sonic CD. It was on iOS but also on Android, PC, PS3, Xbox 360
Rayman Classic is not even on Android and so far there seem no plans for it (unlike for Rayman Adventures where it was known it will be released but with delay, here we know nothing).
Second, the game is listed to be compatibile with iOS 7 which actually gave me hope I can play it on my iPhone 4 but no. Game hangs on Ubisoft logo screen. Now I must be honest, when we look at Ubisoft's port history (Rayman DS, Rayman 3D, Rayman 3 HD), we can see they are not that good and that all those ports have some serious flaws but this port takes a cake. Can't even start game. Which is shame because this version has many achivements and leaderboards.
Ubisoft, bring this on Android, PC and consoles so all fans can enjoy. We all know what happened with Rayman 2 iOS version. That never came on Android either and in the end was removed from store. I hope I don't sound too harsh but I must be honest because I want Ubisoft to improve and fix issues.