I actually have X-COM running quite decently on my Sony PSP which runs at only 333mhz. PC hardware and operating systems are designed to execute and run a plethora of tasks where a mere game console is designed to dedicate it's resources only to gaming. This is why console emulation on PC often requires a lot of processing power, even though the game console is quite "weak" on paper. This is why it could work on the iPhone/iPad. Did you know it can run Amiga games at full speed? Eventually the performance all depends on the quality of the code/port and the understanding of the platform it is running on Hopefully the developer won't give up easily and keep the updates flowing. Projects like these often die fast.