I should really stop caring about how good my service is. I always end the day above 95% but I freak out when a customer may wait a bit too long. It's not like I'm actually working...
Fliers scale like walking enemies but there's absolutely no way to path them. And moving every single tower to try and max out damage to them and back again for the walkers is tedious.
Would have had to deduct points if there hadn't been a mute button in the game. Sorry, but the music is just too annoying for me to listen to for more than five minutes.