I've already beat it. It was my first KH game ever. The last few months though, I've also 1/2 beaten the first, and 1/2 beaten re:chain of memories. I completely beat KH2.
Awesome game. I'm addicted. Xion is now now my favorite character, and, admittedly, I cried a little when she died.
Side Notes: KH3 is a different game from Birth by Sleep, and will come out after two currently untitled side games, one of which is about Sora and Xehanort. And according to (fan) translations of coded, it involves Sora rescuing Roxas, Xion, Namine, Aqua, Terra, and Ventus from the fates that befell them. I smell time travel.