I downloaded this, and got pretty frusterated at first, but the more I play, the more I like it!
I played two fighters all the way through and found a few tricks.
Ninjitsu is surprisingly effective. The quick attacks seem to interrupt enemy attacks and hit them in a good pattern of high and lower that you seem to get more hits in, and make no mistake - those hits are lethal. Also, I drop kicked a bat, LOL. Also, carrying a shield while fighting hand to hand is very effective, as you'll have a defensive option and it doesn't take away your shield arm (why are they all lefties? lol) for fighting.
Jumping and attacking, if you can coordinate it right, seems to do a special attack that I find is a good way to open a fight, and if I'm lucky, end it quickly. Note that tapping to the right or the left (twice maybe) and jumping gives you a quick move that will let you attack as soon as you land (unlike rolling). Caught more than a few of those shield goblins/thieves with my blade like that. There's a backflip too, at least with the wylvan.
Dual wielding weapons is mighty, especially until you get the hang of competently fighting.
Timing. Agreed on the pattern of attacks and timing, but wanted to point out that, since your character will do (semi) predictable patterns of attack as well, you can use that to your advantage. Take two swings with your sword as you're approaching a group of 3 or more, timing the 3rd and fourth to be in the thick of them. The spinning attack can outright kill a goblin with enough skill and strength, and the thrust that comes after it can be aimed at an archer or shieldless foe to take him out of the battle early.
Try to focus on one at a time, as in any game that doesn't weaken foes as they're damaged, though using a slash that you know won't hit your target at one who steps closer isn't a bad move.
Pay attention to weapon lengths - they have attack ranges, and they're nice enough to let you know about it. I can tell the difference between a stubbier rusty axe and a longsword.
I haven't been able to find any heavy weapons or large pole weapons to suit my fancy yet, but I think the combat is great fun. Pressing R to instantly resurrect oneself cannot be overlooked either

I thought mine was going to wear out before I bagged my first goblin lol. The combat is great fun imo.