Unfortunately IOS Ragnarok is for some weird reason not available in my country so I didn't get a chance to play it
but from what I saw on youtube etc it is way simpler game compared to PC version
also since you mentioned that it is a single player game - it is way easier to make single player game than multiplayer (mmorpg)
if you want to merge mobile and PC versions it can bring more issues - controling character would be harder, chat would be way harder etc - there would be big difference in gameplay/balancing causing lots of complains and unhappy players
also, when you use some of commercial game engines - licencing gets messy / too expensive
for example Unreal engine - to be able to make MMORPG price for licencing is huge, and you need tons of people etc and there is royalty % you have to pay etc - far from profitable solution
another problem with mobile games is file size - I'm not sure about Android but I think IOS file size is limited to 2 GB
updates would also be a problem as most of the time when you update your game etc it is not a small patch but a whole app instead which might make it not very attractive because of data transfer charges by most mobile providers (well, you can play at home etc through wifi connection but still it can push away lots of customers)
then there is content optimization
(unfortunately I don't use any Android devices - only i-junk so can't tell for Androids)
devices have small amount of RAM that is used not just for loading game into RAM but also for sound, GFX, all those models and textures, etc
with some dynamic loading/unloading of data it could be possible to make it work as a single player game since you won't have to load tons of outfits and weapons etc at once unlike if it was done as MMORPG
just think about how many different player models etc are displayed on screen when you walk in Junon - it lags even fast PCs, and that would turn (in case you managed to run it on your mobile device somehow) your game into slide show
on the other hand making some IOS/Android games (not MMORPG!!!) won't be that hard although it still takes lots of time and manpower and $
Edited by Xenobite, 18 April 2012 - 04:19 AM.