A genetics based simulator, potentially allowing the player to breed, raise, train and compete various animals. Breeding would need to be fairly complex and realistic - penalties for inbreeding, appearance variations in crossbreeds and suitability and inborn skills inherited from parents. The main difference between this and similar games, such as Howrse or Lioden, would be the ability to focus on more than one species of animal. Players could train race horses and breed show dogs as a side business, for an example. Animals would need to be kept in an appropriate space, fed, watered, exercised, groomed and otherwise looked after each day.
The game could be made interesting through first person game play - actually riding the horse for training, feeding the cats by hand and other activities.
Cats, horses and dogs would be the most realistic animals to work with. With the number of breeds and color variations you could probably hand out achievements for collecting all possible coats within a breed.
Inspired by Lioden, Howrse, Furrypaws and similar sites.
(If you go on Howrse, the person who referred you is Cheshire_Piano)
(If you join Lioden, #54186 referred you)
(if you join Furry Paws, use this link)