A lot or a little?
Parents need to know that Cat Physics is a strategy puzzle game that requires a good working knowledge of physics. Not that you need to know forumulas, data, or even the names of forces like momentum and velocity -- but you'll need to understand what happens when a ball of yarn is tossed in a certain direction. Or against a wall. Or over a ledge. The content is cutesied up, with nothing objectionable for younger kids.