3 years too late to chime on this... But for reference I guess I'll say that to attack, you hold down the Right Mouse Button and swing you mouse across the screen and you'll attack with your current weapon. Just make sure to press A or click the crossed swords button so you are in combat mode

You ever find out the answer to this question?  I think I can look it up...

I just started to play this game & the only thing I can't do is attack. Does anyone know the button to attack.