Both boys and girls, especially animal lovers, will enjoy this game (see below about sensitive animal lovers.) You spend a good deal of time interacting with the horse (more jaded players might be annoyed by this) and though the main character is a boy, he's following the direction and story of a woman.
Even considering that you play the game sitting, it can be a real workout - I've been playing, myself, and am finding myself stiff and sore after a session of outrunning and outgunning Hobbes (little gnome-like creatures.) There is plenty of action, intrigue, and puzzles that prevent this game from becoming Kinectimals.
The game does foster cooperation and caring; the hero reluctantly agrees to take on magic to save his horse, but decides to follow on with the quest after he sees how other people are affected by the evil he fights. Violence is fairly low-key (although the bugs do explode when they squish) but the "boss" creatures can be frightening. Most importantly, the horse takes the brunt of your mistakes, and you watch the horse die if you fail in a horse-cart-based challenge.
In fact, the horse screaming in pain can be a serious issue if you have a sensitive child, although your character has the power to heal. Removing arrows and splinters from the horse, for instance, can take some perseverance and patience; you sometimes have to try several times, and the horse cries out when you fail. However, you do get time to "bond" with the horse; it heals completely and shows appreciation, and every time it "dies" you simply restart the level.
Note: Glitchy controls can be addressed two ways: one, by recalibrating, and two, by sitting against a contrasting background (we drape a white sheet over the chair.)