Ignore the reviews from the so called professional film critics. I have read their reviews. It's over their heads.
It all comes down to this: If you liked the first movie, you will love the second version more. More robot action, more battles and no plot dragging, even though their were some holes in the plot.
The movie will be fine for a 12 year old. There was a couple of s bombs and two dogs going at it for a few seconds. The movie had it's share of comedy as well, even though Mudflap and Skids get annoying after a while. The violence was pretty much of the cartoon variety, just like in the first one.