The closest game to Ni no Kuni in terms of gameplay would be White Knight Chronicles... With little bit of Pokemon and Atelier games
I love the world, I like combat on Normal mode, but I can not get much into the main character yet, I think I am to old to be able to fully see the game with his eyes
And the world is typical JRPG "Open World"... you can travel around very big areas, but, new areas are unlocked by the story...
I realy can not tell you more accurate info, never played any DQ games
But for me, it was well worth 60 EUR...