I have only played the first one, but if I may, I will share some of my thoughts on it.
I've played several modern RPGs, namely Skyrim and Morrowind, among a few others. Those are all fantastic games, but there's something about Two Worlds that makes me have more fun when I play it. It just has that sort of mood that doesn't take itself too seriously. It's hard to sum up in a few lines, because if you describe the elements of the game, it sounds pretty dull and awfully awful.
The dialogue is thoroughly Mozzarella (or maybe Colby), and everything about it is terribly dramatic. No matter how small the problem is, whether the town might be massacred by ogres, or a father said "no" to a proposal, all lines are delivered in the same imminent-danger sort of tone, delivering their strangely awkward lines in Ye Olde English. The voice acting is some of the most poor quality I have ever heard, and yet, it's also one of the few RPGs where I have actually stopped to listen because it was so entertaining!
More than any other game I have played, I really like the item system. One of the pivotal points of the loot system is that you can combine any two similar objects to form a better, single object. It's always really cool to come upon a set of armor identical to your current one and be absolutely thrilled with the prospect of combining them! Speaking of, all the armor designs are all really cool, and a bit over the top. There are over 550 sets of armor, meaning there are over 2000 individual pieces, along with dozens of weapons. Even so, they all have a distinct look that makes you want to collect the different sets. Every time I pick up a new piece I'm surprised to find that they made yet another unique look for a set of armor.
And, more than any RPG I've played, I get an immediate sense of just how cool a particular item is. When I pick up a yellow item called 'The Killer's Great-sword of Wrath' in another game, I say, "Eh." When I pick up 'The Black Terror' in Two Worlds, I say, "Woah! This is fantastic!" It simply has that sort of hook that I really enjoy. The names are creative and give a sense of how much an item is worth or what it's geared toward.
In a final analysis, it's the kind of game you can look at and not think much about. Cheesy dialogue and voice acting, unbalanced armor, mediocre mechanics. But when you put it all together, you have an experience- you see a mountain in the distance and you say, "I want to go to that mountain." You find a village blighted by sea monster attacks, prompted by an angry god. Then you finish with the town, after doling out justice and helping (or ruining) people. Then you find a road and say, "I want to follow that road."
And then you get slaughtered by a Minotaur. But that's my experience of Two Worlds!