I've put about 6 hours into the game now, so let me qualify my initial impressions: Yeah this game gives a terrible first impression, and yeah it does get better, but not a whole lot. First of all, a lot of the major issues I had during my initial time with the game still exist. When you fight your very first battle in this game do you want to know what the first thing you'll notice is? The incredibly choppy framerate. Look, I normally don't care a whole lot about framerate (30, 60 -- whatever) but it's really, really jarring in this game. This problem never goes away, you simply start to get used to it over time, but that doesn't make it any less of an issue.
Now one thing that has gotten better are the empty and voiceless cutscenes. Nearly all of them as of late have been fully voiced. However, the lip sync is still just as bad as ever, and I think that makes some cutscenes especially awkward. I can easily forgive this, but it tells me this game lacked polish. Lots of it.
But back to the meat of the game. The world here barely feels inhabited. There really isn't much to do. And the game does a poor job at directing you towards the next big thing. The games combat consists of two buttons, they give you a block or guard button but it's impossible (and kinda pointless) to use. They also try to freshen things up by giving you quasi-control of another single party member. This is mostly important for the game's somewhat limited environmental interaction. Now another compliment I'll give the game is its party system. It's pretty awesome having up to 12 friendlies on screen -- even if it does marginalize the players role somewhat.
What appeals to me about IU is that it's an action RPG, it's open environment, and it doesn't have random battles. I love that. I loved Final Fantasy XII for that. But all that said, IU is a game that lacks the labor of love that turned FFXII's decent game mechanics and okay narrative into a really fun (and unique) game experience. You can tell. Play the game yourself if you're really curious.