I'm a huge fan of the Kingdom Hearts franchise, and this installment is no exception. It's probably my favourite in the series thus far, behind the original and Birth by Sleep.
For newcomers, the plot is a lot to take in, and kids under 9 would probably have a hard time keeping up. The game does an excellent job of summing up 10 years of KH history through written summaries of previous games though, so if you're willing to do a bit of reading you can probably get the gist of what's going on.
The gameplay itself is simple enough, but you can customize your deck to suit your own fighting style, which I really love. You can also earn abilities by playing with your Dream Eaters, which I enjoyed a lot more than I thought I would. Taking care of your little party members has an addictive neopets quality to it, and being able to take pictures with them is a pretty cute addition.
I think the CSM review here is really overplaying the violence here - the enemies are so colourful and cartoonish that it looks like Sora and Riku are beating open hoardes of pinatas. No blood or explosions or anything like that. C'mon, give your kids a little credit here. The speeches about the power of love and friendship (of which there are many) definitely outweigh the violence.
I totally loved this game, and I'm now on my second playthrough. It's a must play for any KH fan, and a great way to introduce someone into the series. Don't dismiss this one as just another spin-off!