It's very fun to just fly and bring hellfire down to them puny humans, the feeling of freedom and power this game gives is very satisfying. Gameplay in this dragon simulator is mind numbingly addictive.
The game also has a lot of cool medals and highscores, very important for endless arcade game.
Also graphics are really good in this, I like how the Dragon looks and his fire is epic.
Two things to improve to make this perfect:
1) It would be more cool if avoiding enemy missles were a plausible strategy. The current optimal strategy is to maintain a steady certain altitude and it's not that fun as avoiding and changing altitudes. The enemy missles that are able to pierce armor after all upgrades should be rarer and increase in density much more gradually, to compensate that they should be more damaging and no altitude should be more safe then other.
2)The health drain is unnecessary in my opinion and bleeding without any cause doesn't blend well with being a mighty dragon.