Is there any tactics to fighting? It seems hard to timing counterattack, or should I just spam attacks and roll/dodge?
Timing dodge, not counter attack when fight in group.
When in combat, you can quick change signs by pressing/hold L2+left or right dpad.
Learn to use signs especially quen.
Oil also important because of extra damage.
That's the only tips i can give so far.
This game isn't supposed to be easy. The combat is intended to be challenging, and if you don't like it you're doing something wrong. I've watched game clips of many people who are complaining, and have noticed two common trends. They either don't dodge enough, or they dodge too much.
You have to keep moving in this game, especially if you're surrounded. You'll rarely have a chance to spam attacks if its more than 2v1. Dodging is something you should do often, as it uses no stamina; however it shouldn't be the ONLY thing you use. This game has rolls, parrying, ripostes, quen sign, bombs, and potions for a reason. If you learn how to use all of these in the correct situations, the combat is one of the best systems in any RPG.
Rolling - Should be used if getting swarmed by creatures that attack quickly/use heavy attacks. (Nekkers, Water Hags, Drowners) Also to apply Quen if it comes down, however rolling does use stamina so you'll have to wait a second to bring it up.
Parrying - So you're surrounded and getting the crap kicked out of you. You're desperately watching your health bar drop as monsters mercilessly tear away at you. Can't dodge or roll, you're trapped. Parry. Geralt's witcher senses give him jedi-like blocking skillz. Granted there are attacks that are too heavy to be parried, but in most cases it'll give you a couple seconds to get your bearings/enough stamina to cast signs.
Ripostes - Require precise timing, so I wouldn't rely on using this instead of parrying. I seem to only get these in intense flow battle moments, and parrying is usually the safer option of the two.
Quen - Should ALWAYS be up if possible. Use it before going into a fight and you'll go into a fight with a shield and another available sign; stamina regens quicker out of combat. If it goes down, get it back up ASAP. If upgraded with the first available skill it also explodes when it goes down, with dmg and a chance of knockback, which comes in handy if you're in one of those cornered situations.
Potions - Do I really have to mention the importance of these? Considering they all get refilled after meditating providing you have Alcholest (which you more than likely have tons of by now) there's no excuse to not use them. Swallow is one of the most handy potions, and should be crafted as early as possible. Plus theres a quest in White Orchard that gives 250 xp just for crafting it (this quest fails after leaving the area for the story).
Bombs - Not so hidden gems. Know how drowners hate fire? Know how you hate fighting drowners? (I have a vendetta against them) Use bombs! THESE ALSO REFILL WITH MEDITATING. So no excuse not to use them. Dragon's dream produces a noxious gas cloud that when combined with igni, creates an explosion obliterating anything unlucky enough to be in it (including yourself, be careful!) Grapeshot does shrapnel and silver damage.
Finally just a couple run of the mill tips.
- Careful where you're standing, positioning is unexplainably important in this game. Watch out for little objects on the ground that Geralt can't jump over for some reason.
- Save FREQUENTLY. If a monster makes you think "Oh no" then save. If you see a group of monsters, save. If you discover/clear out some undiscovered locations, save. If you complete a quest, save. It may take all of 5 seconds, but it's better than being sent about 15 minutes back because the autosave didn't decide to activate.
That's all I got. I understand that some people simply will not like this game's combat; however I implore you to at least learn and practice before you simply say it's bad. As mentioned previously, it's supposed to be challenging. If it wasn't challenging, it wouldn't be rewarding. It's not broken, just takes some time to get used to. This game is a masterpiece and I think CDPR did amazingly on it. Sure there might be some technical hiccups, but they obviously aren't intentional; and if you think it is you're being a conspiracy theorist or don't know how much these guys appreciate their fans.
Thanks for reading =)
SOSLetho. Such a badaas