The site is very tween friendly and at the same time very safe. If I were a parent the only problem I would have with this site is that my children would spend too much time on it because it seems quite addicting. Here are a few screen shots of what the Penguin World looks like:
So far this site seems pretty cool. I wish I had something like this as a kid. I think my parents would have been willing to let my siblings and I go online more often if we had a tween game sites like this one.