Fandom Rivalry: With Dragon Vale. Many people hold DragonVale up high for being the first dragon breeding sim game, and often call the more-popular Dragon City a "ripoff" with terrible dragon designs. Dragon City fans shoot back by criticizing DragonVale for its lack of battles and fun activities.
Popular with Furries: While the game is relatively obscure, there are still quite a few scalie fans that are drawn to at least one of its many dragons.
Squick: You can breed dragons with the baby skin together, and even breed baby-skin dragons with adult-skin ones. Sure, it's G-Rated Sex, but it's still "sex".