For example using an object with 2 different coloured sides. When on side red it represents swings with your weapon, when you use the other side you block? Would require practice and a object shaped a way that switching sides would be practical for use. For movement you use a strap-on controler on your free arm. Thats how i imagine it anyway, well im sure people will find a solution for playing these kind of games
Sounds like too much effort for a very basic motion control that you are still going to get brutally owned with, I can't see it being very fun either, I find all of the current motion control technology boring and 'stiff' as hell, these things just never seem to be fluid enough for it to feel enjoyable to play, but that's just my own opinion of course.
