My kids adore this game!
This was purchased for my 9 year old son, but my 6 year old daughter picked it up quickly and easily. It's literally the title - you're a plant, destroying zombies in your garden. It's really silly. There is nothing offensive here, other than the shooting of the zombies. Even that is hardly bad, there is no blood, pain, or gore. It's a lot like Looney toons in the silliness department. I don't like the in game purchases, but those are unavoidable these days. No language or thematic issues. I would let any child old enough to play video games try it.