I watched it a couple of times, but just now i understood the idea of "correcting blow with mouse". Thanks Sir Doyle.
As for sparks - we may see when there are too much of them - ie. PVKII, but then there is also a "stun" effect after blocking heavy blow...
To all sword-fighters here - does strong blow really knock you out of balance, "stunning" you for a while? Making your arm hurt and disabling it for a while? It may be a cool feature if balanced properly IMHO.
I'll definitely be sticking around, maybe even keeping my eyes open for possible beta tests. 
