It's a combat flight sim from 1989. You fly your jet fighter through 5 missions, blasting your enemies out of the sky. There are several types of aircraft to battle, with limited ammo and fuel to do the job. The big bomber planes can only be destroyed with homing missiles (or 25 machine gun shots, which isn't really feasible, as you'll see in the playthrough). Unlike many 2600 games, this can actually be completed with an ending, and what an ending it is too.
On a technical level, this game is impressive for the 2600, though gameplay wise, it relies a bit too much on luck over skill for my tastes. You can’t really dogfight the enemies properly, so you just have to dodge from side to side, hoping they’ll get in your line of sight. Also, the parts where you need to fly around looking for the next wave of aircraft drag it down, due to the confusing radar system, which never behaves how you'd expect it to. Making the bombers easier to destroy would have been more fun too, as the homing missiles aren't very reliable.
Anyway, gripes aside, this is definitely a unique game for the Atari.
I don't think the easy or hard settings affect anything in this, but I put it on hard just in case.