(NOTE: This review is not about the games, the bears, etc. This is about the behaviors of the people themselves. Also, keep in mind, there are some very nice people on Bearville too.)
If your child uses Instant Chat, this game is appropriate for 5 and up.
However, if you use Safe Open Chat, I recommend 8 and up. The reason for that is mainly because of dating. Don't get me wrong, the dating isn't NEARLY as bad as Club Penguin (on CP, people always walked around doing hearts, but on Bearville, I hardly ever get called "cute" or am asked to date.)
By going into the Furbulous Fashion District, it's common to see guys and girls have date talk, call each other "bridges", and things like that. However, with Instant Chat, you can only speak from a list of pre-approved phrases, and you cannot see conversations made by people with Safe Open Chat. In Safe Open Chat, words are censored, but you can make your own sentences with the words that aren't. However, this gives people opportunities to "date talk" and use foul language (calling each other "bridges".)
About a year ago, I was so mad about all the daters, that I decided to experiment. I made a male account with black hair, black shades, and black clothes. I stood in the Furbulous Fashion District, in front of the Theater. Soon enough, a bunch of girls came up to him, doing "Friendship" emoticons (which have hearts.) One girl even wanted to date me in the Coffee Shop... uh, no thanks.
HOWEVER, if you use Instant Chat or Silent Chat (where you can't chat, but you can just use emoticons), you likely won't have to deal with the above. You can just freely play games and enjoy your time, without encountering daters.
Sorry for the long review!