Riddick: Escape From Bucher Bay

[Quietus]

Anybody played this game? How do you block/evade the punches and uppercuts? Sometimes, Riddick just blocks the uppercut and kills the guy (while doing hand to hand, not when sneaking up from behind). Don't know how; it just happens when I'm clicking furiously . There's no manual just the quick ref card.

I can do mouse2 (right button) but it doesn't block anything at all.

Is it tied to the difficulty level? I'm playing on Hard difficulty.

Thx