The good news is, it's rather fun and addictive with a lot of cool dragons and habitats, plus competitive events and other niches like battles that make the game fun to learn about and let you win cute special dragons. The bad news is, you will never have all or even most of the the dragon types, and that's my big disappoinment. Many rare ones can't be bred. They must be either crafted for an exorbitant amount of dragon essence (which takes 8 hours a piece to get) or bought for an average of 400 "gold," which is actual money, bit currency you earn in the game. 500 costs $20, so figure you are paying $20 for some of the dragons, with the rarest ones costing almost $200 (4,000 gold) - ridiculous! The other activities, such as breeding, habitat building, hatching eggs, also take several hours each on average.
The gold unfortunately isn't freely given or won during the game, but a little patience with watching ads and spinning the wheel during special events gets you generous rewards in food and game currency.
Bottom line is, if you're willing to treat it as an idle game, you like collecting cute dragons, and you're settled that you can't get all thousand varieties, it's a good game for you!