I found the second game to have more game, but also it felt sorta...low budget?

Ni no Kuni 1 felt very much like "what if ghibli made a JRPG". The second one loses a bit of that, and the production values seem a bit lower around the edge. Lot less voice-acting, seems to go more broad than deep as it were. I didn't hate it, I think the combat was an improvement and the castle building stuff was fun, but I honestly probably liked my time with the first game more overall.