I adore Kingdom Hearts. The first one was one hard son of a *****, and I played it when I was pretty young, so some parts of it took me an eternity. (I never beat Sephiroth!) Two was also pretty amazing, but lacked the reward of the challenge that the first one had. By that I mean it was piss easy and a four year old could kick its ass any day of the week. Chain of Memories, in my opinion, was balls. I didn't like the weird card combat system at all, and Riku at the end of the game is impossible. 358/2 Days is okay. I'm playing it right now, not far into it at all, but I think it's average. Hard, like the first one, but for some reason it doesn't appeal to me in the same way. Maybe I'm just bored of visiting Agrabah for the uber-bazillionth time. I believe that they need to get some new worlds. Maybe reverse the roles, have us go to places from all the 50 Final Fantasy games out there and have Disney sidekicks. Just a thought.
That is my very detailed, long and monotonous opinion. Feel free to take naps while reading it.