The good news: I fixed a bug in my Flash detection code so that it now works in Opera without the right (and still without any) Flash plug-in. That fix (version 0.51) should make it work on the Wii, too ("work" in this case means "no sound, but at least you can play the game").
Concerning other browsers, some people seem to have tried IE6 and very old Safari versions which I cannot test, and both do not work. Let me quote from my own post over at Tron-Sector:
Jangaron is based on CSS border slants, which are not fully functional in IE6. One crucial feature, namely transparent borders, is missing in older IE versions, and Jangaron heavily relies on that feature.
Thank you for starting to report problems; now, let's analyse and fix them if possible!