Dragonvale

Dragonvale is a park sim along the lines of FarmVille available on iOS devices. The player runs a zoo/conservatory for dragons, and they must purchase elemental habitats and dragon eggs, as well as breeding new species of dragon. Dragons collect coins based on their type and level, and levels are increased with dragon snacks (which in turn cost coins).

Tropes used in Dragonvale include:

Bribing Your Way to Victory: Food, coins, and the rare crystals are all available for purchase for real money. Getting them, especially the crystals, makes the game far, far easier.
Dem Bones: The Halloween-exclusive Bone Dragon.
Elemental Powers: Most dragons are classified in eight elemental types: Green Thumb, Playing with Fire, Dishing Out Dirt, An Ice Person, Shock and Awe, Making a Splash, Blow You Away, and Extra Ore Dinary.
- Elemental Rock-Paper-Scissors: Most elements have a opposite, which they cannot be bred with (fire and cold, or earth and air, for example), unless you create a hybrid first. They will also be affected negatively by the Boost item for their opposite element.
- Infinity+1 Element: Originally Rainbow, Sun, and Moon; which had their own habitats and couldn't be bred with dragons of other types. Later surpassed by Gemstone Dragons, which have their own island, can't be bred period, and generate crystals instead of coins.
Everything's Better with Rainbows: One of the rarest dragons available is the Rainbow Dragon.
Experience Points: Most actions, from feeding your dragons to clearing away dead trees, will net you experience.
Floating Continent: Your zoo is located on a floating island. As you level up, you can get a whole archipelago of islands for your zoo plus the crystal-only epic breeding island.
Follow the Leader: Of FarmVille, which was itself following other Facebook games.
G-Rated Sex: Breeding Cave descriptions admit that nobody's sure exactly how breeding happens.
Gotta Catch Em All: All the different breeds of dragons, including 3 rare dragons and holiday only dragons. There's even an achievement for it, though some of the rare ones aren't strictly necessary to get it.
Holiday Mode: The islands change with the seasons, being snowy in winter and green in summer. There are also season-themed decorations for the islands and holiday-only dragons which can only be bred in the month surrounding their respective holidays.
Hybrid Overkill Avoidance: There are many crossbreed dragons, but when hybrid dragons breed their offspring will usually have two of their parents' types; no more. Though there are a couple of exceptions when it comes to holiday-only dragons (the Panlong Dragon has the four classical elements; the Love Dragon is fire, lightning, and plant). The Rainbow Dragon is also implied to have all eight types at once.
In-Universe Game Clock: Everything in the game runs on real time. Dragons earn coins per minute, food crops take between 30 seconds and one day, depending on amounts, breeding dragons takes hours, as does hatching eggs and constructing habitats.
Isometric Projection
Last Lousy Point: The Leap Year Dragon. It's not required for any achievements or anything, but most holiday dragons are only available for a few weeks a year. The Leap Year Dragon was instead only available for a matter of days, and won't show up again for another four years.
Our Dragons Are Different
Palette Swap: The Blue Fire, Frostfire, Plasma, Current, Leap Year, and Sandstorm dragons are recolors of the Fire, Cold, Lightning, Water, Rainbow, and Air dragons, respectively.
- Head Swap: The Clover dragon, which has the Flower Dragon's wings and body with minor alterations, but an original head and tail tip.
Power Crystal: The Gemstone Dragons.
Pretty Butterfly: The Butterfly Dragon
Punny Name: Several of the default names for the dragons are very punny, either ironically (Speedy for the very slow Earth dragons) or straight (Faraday for an Lightning dragon).
Ridiculously Cute Critter: Most of the dragon babies. The ones that aren't are usually Ugly Cute.
Ugly Cute: The Cactus Dragon.
A Wizard Did It: Quite literally the explanation for everything from why you can have frozen patches of ground for your cold dragons to how your islands are constructed and summoned.