Lots of potential hampered by lots of poor design choices and a weak story
First of all, the game looks really good, with great textures and lightning. However, it is also so over-smeared with bloom that you might need sunglasses to play it. This also all but removes any scenic vistas where you could gaze over the landscape as everything becomes blurred just a few feet ahead of your character.
On top of that, character models are rather bad, especially the arms, and the animations are stiff (your character looks like Forrest Gump when running). All in all though, you could go worse with the graphics, and there certainly are some eye-candy to find.
Onto the sound, the music is really good, fits the setting and atmosphere perfectly, so no complaints there. Voice acting leaves a bit to be desired, with your character always sounding grumpy and sarcastic. Not a lot of emotion in that guy. Sounds from monsters, fighting and ambience are nothing special, but does the trick. As a whole, the sounds are fine, but not great.
What's the gameplay like then? Well, it's a mixed bag. The developers had a lot of good ideas, but many of them are rather poorly implemented. Crafting is great, which allows you to upgrade your weapons and customize your armour with colour schemes and magic crystals. However, the user interface is awful, there is no stacking of identical weapons, meaning you have to select everything piece by piece. You can use some shortcuts with ctrl+LMB as well as remove item confirmation, but it's still unnecessarily complicated. On top of that, all icons are huge (making this game perfect for grandma!) and things like damage and protection is described in symbols rather than text. I still have no idea what rings do to protect you, but I think a high number of "stars" is positive...
Combat looks pretty good, but becomes repetitive. In the end, you can pretty much finish the game by spamming the LMB and use the occasional block breaker, without much finesse. It's not awful, but not that great either.
There are some serious balance issues though where you can happily kill some goblins for a while without too much hassle, until you suddenly face some sort of super goblin that is about 200 times as strong as the previous enemy (not exaggerating here). No warning, no clear signs, just another identical enemy that for some reason cannot be killed but who will kill you in 3 hits. These annoying difficulty spikes becomes less prevalent later in the game, but it can be enough to turn people off in the beginning.
Loot can be immensely rewarding at first when you find a new set of armour or a shiny weapon, but as soon as you find one of these, everyone else are going to start having them too, and the stores will only stock the latest high level stuff from then on. There is hardly any unique equipment in the game at all.
Quests can be fun, with the main quest and random side quests generally being rather original and well written. However, they are also very simple, and be mostly be solved by just going from quest marker to marker. Then there is a seemingly endless supply of guild quests, which are not so great. These are simply given through a piece of paper, and are generally either "fetch this item" or "kill these monsters". They are not very fun, and get old really fast.
As for the exploration, it's pretty disappointing. Sure, the world might be pretty to look at, but it lacks any real interesting vistas to give you that "whoa" feeling. Caves and dungeons all look the same and are really boring (although still pretty), and the world is mostly empty (aside from annoying mobs everywhere), with few surprises to make it interesting. The cities are more fun to explore, but fail to stand out and look mostly the same all over.
It's not really that open-ended either. You are limited to four islands (of which one is really tiny, and the biggest one is mostly cut off into two smaller locations. On these islands you are mostly confined to smaller paths surrounded by cliffs, and certain areas do not become unlocked until you reach a certain point in the main quest.
Finally, what would an RPG with be without a good epic story and some good dialogue options? Not much, and here is where one of Two Worlds 2's biggest faults are.
There is very little you as the player can do to influence the dialogue, and quests generally only have one solution where your options are to either do the quest or not. There's barely any moral choices, and little consequence to your actions.
The main quest is confusing and not at all rewarding, and just as you might find yourself interested and have an idea what's going on, the game quickly changes focus and throws into a new location, leaving the quests you have done in other regions feeling unfinished and unexplained. For most of the game, I had no idea what the heck I was trying to achieve in the story aside from the basic "save your sister" bit from the beginning (which is also not very well explained, being a remnant from the first game that I didn't finish). When I got to the end revelation and the "big twist" (which is pretty awful and made the whole main quest seem even more stupid) I just said "oh, but come on!" and shook my head in disbelief (though there were probably a few cusses and some lol's at how bad it all tied together as well). This was then followed by a crappy boss fight and an even crappier ending, which leads me to assume there will be yet ANOTHER Two Worlds.
If the developers try to come up with a half-decent story, get some better voice acting, add some real role-playing options to add more replayability to the story and tweak the balance in the beginning a bit... and you know, get a better name than "Two Worlds 3"... another game from them might actually be pretty good. This one on the other hand, I would only recommend if you have already exhausted your other RPG's from BioWare and Bethesda.