I think the negative reviews are probably because ...

I think the negative reviews are probably because you must become a paying Star Rider to advance beyond a certain stage. My recommendation is to pay for the lifetime! Our entire family (children, parents and grand parents) all play. They add minor content on a weekly basis and major updates (new horses, new regions, new parts to the main quest) several times per year.

It is kid friendly, and that will become immediately obvious when you try to use the in game chat which is affectionately named "Phil" by the players after the over-zealous filter on it.

It really is a fun game to play, we have been playing solidly for over a year now and while we have run out of main quest, they promise more to come soon! But even without quests you develop friendships, you can train your horses and participate in championship races, etc.