Well, it delivers what it promises. But it's not the most fair game in the universe.
For starters you can simply shoot straight left or right to kill every single ground bug that comes from either direction. The only reason you have to leave the nest is to eat. However almost no matter what you do your nest's health will run low or out completely by wave 5 simply because of the flying insects alone. Not only are they too fast to shoot out of the air, but they have enough health to take out a sizable portion of your nest even as you shoot them down.
It's quite frustrating to be shooting as soon as possible at one and still see it cost your nest near a third of it's life.