Please define "properly", at least regarding Linux.
There is a performance hit under Linux, sure, but beyond that?
I'm using Linux myself full-time, but for flash games I might even consider Linux irrelevant if there is no way of getting good performance.
The by far biggest part of the audience still uses windows and that probably won't change for quite a while.
I'm using Linux myself full-time, but for flash games I might even consider Linux irrelevant if there is no way of getting good performance. The by far biggest part of the audience still uses windows and that probably won't change for quite a while.