While famous on internet comments, it's not really used in any of the world class games like Asphalt.  The leap in graphics from Asphalt 8 to Asphalt Xtreme was xtreme, yet even the best Unity examples can't compare with Asphalt 8.  While acceptable for millenials to rent software, it's not acceptable for old timers to invest a lot of time a toolkit they can't own.  Having said that, if you're not spending a lot of time on artwork & don't expect any revenue, a canned game engine like Unity might be the way to go.  Many programmers started their own game engines in the late 90's, to end up nowhere.

Besides a real detailed rocket model, lions wouldn't invest any time in scenery.  Ideally, there would be a way to use Google earth data, but no game has done this.  

In years of trying to find the essence of a great game, it would be realistic physics, realistic graphics, continuous achievements, unlimited lives, adaptive AI.  The physics in Asphalt are very realistic, have many cues showing the player interacting with the environment, but have just enough tweaks to make it playable.   Games that make you start over after running out of lives are unbearable.  Unlimited lives with a time penalty or a score penalty are the way to go.   If the AI adapts based on the human player's skill level to keep the score close, it's much more engaging than a complete wipeout.  Everything else in a great game, whether it's a driving game, flight simulator, 1st person shooter, or ball game is almost a mcguffin.  

Games have shorter lifespans than programming languages.  Kerbal space program was once a game with some kind of achievements, but for many years has just been used for crude rocket simulations.  Lions briefly wrote toy games many years ago, but it will probably never happen again.