How about a timed trial?
It's awesome that it supports Windows RThowever on x86/x64 you would be hard pressed to get users to pay ?4.59 for an emulator due to the insane amount of free ones out there such as Project64.
So I would say a time trial would be must so users can reassure themselves that it works (not saying it doesn't) on their device. As once you start hitting that ?5 barrier an app is subjected to heck of alot more criticism then an app that costs 70 pence for example.