Flak

Flak looks and plays a bit like an earthbound Zaxxon and nothing about it is terribly new. But it's a challenging game that requires some almost impossibly fine maneuvering, quick trigger reflexes and ESP.
112 years in the future, a psychotic computer threatens life as we know it - or as we will know it in 2096. The player is cast as a fighter pilot whose mission is to get to Computer Control and put the non compos CPU out of commission. As usual, nothing less than the freedom and happiness of mankind hangs in the balance. Unfortunately, this one or two-player contest is so often frustrating that the CPU in danger is more likely to be the player's own.
The jet has to cover a lot of territory to reach the primary target - territory that the instruction booklet describes as "awe-inspiring". Now, these graphics are perfectly reasonable, but they hardly leave you breathless. They look like a mixture of aerial reconnaissance photos and first-year geometry - all the flak batteries are tidy orthogonal shapes which fire from dead center. There are a lot of these installations scattered about the landscape and not only can they fire in any direction, they also have unerring aim.
The number of batteries alone add a sufficient frustration-quotient to Flak but the really nerve-wracking part comes when the player has lost a jet. The computer returns to the jet landing-strip and takes control of a new plane until it arrives at the point the previous jet went down. It can be a little hard to tell just when manual control is returned to the player and the Flak batteries take full advantage of any hesitation. Rather than littering the landscape with the wreckage of gallant fighters, you tend to create an aeronautical graveyard of sorts.
Gameplay is pretty straightforward while the player controls the plane. For a fairly simple screen set-up, there's an awful lot going on, and dogfight maneuvers can as easily move the plane into danger as not. Joystick response isn't as quick as one would like, either.
Despite these drawbacks, or because of them, Flak can be a challenging, if often infuriating game. If you can keep track of six things at once while trying to line up a target and possess second sight for where the next attack will come from, give it a try.