Well, in Windows 8 (.0) DirectDraw is very sluggish. So if you want to play JJ2 in full screen you'll get very poor performance. As far as I know it's fine in windowed mode (but I don't have Windows 8 so I may be mistaken).

I know nothing about whether it's any better with Windows 8.1. Hopefully it is. Maybe we should try it out with the preview version that is available now.

Windows RT (NOT: "Windows 8 RT") is a completely different matter. It might look similar to Windows 8 because both feature the "Modern UI" (the weird tile thing), but it is a completely different system underneath. Microsoft failed to make a clear distinction between Windows 8 and Windows RT for non-technical people, so I'll explain. It basically comes down to this. Windows 8 runs on x86 processors, the type of chip that has powered most of our computers since the 1980s and for which all our programs, including JJ2, are written. But Windows RT runs on ARM processors instead, that's the kind of thing that runs your smartphone or tablet. Microsoft has created the "Modern UI" so that apps that are made for the "Modern UI" can run on both Windows 8 and Windows RT. But since all regular Windows programs are written for x86 processors, Windows RT will not run any regular Windows program, JJ2 included. You're stuck with the "Modern UI" apps in Windows RT. So no JJ2.