The game is very challenging and long lasting even for beginners. The problem is that some of the aircraft cannot be controlled and as a result, crash. Other issue is that aircraft enter as helicopters are landing and there is no time to react. It is very frustrating especially when you are doing well and have a high score. I view this as cheating. I continue to enjoy the game during long waits at appointments, but I am always ready for the ever present frustrations and disappointments.