Another virtual horse game I loved to play growing up, and still enjoy, is Horse Isle. Unlike some horse games that are focused on breeding, caring for, and training horses this game focuses more on adventure. In all three versions of Horse Isle you get to select your avatar, including their features, and then enter the world of Horse Isle. Through completing quests, mini games, riddles, and exploration you will find treasures and riches that allow you to buy horses, tack, riding gear, outfits, and so much more. You can travel to different islands and countries where new adventures and horse breeds await.
While there are three versions of the game they are, in my opinion, all very similar. All the versions involve exploring, completing quests, finding horses, etc. all that really changes are the graphics and things like mini games.
Graphics are: 2d (in version I), 3d (in version II and III)
Free online horse game