Airwolf, the helicopter, can't stay still in the air, despite the aircraft being built to do so. This means you have to do everything in your power to ensure that Airwolf doesn't go off course.
The passages are extremely hard to bypass due to the issue in the first point, so you MUST be pixel perfect. Any more than that, and you die.
There is one particular passage that's nearly impossible to pass, an indestructible obstacle is placed in the middle of an already narrow passage, leaving an open space that's just ONE PIXEL taller than Airwolf's sprite. And as if this isn't difficult enough, there's a row of Soyuz rockets positioned on the ceiling of the screen that constantly shoots flames down at you.
A health bar that drains rather quickly. This is because that your helicopter has no invincibility frames at all, despite the fact that you have 6 hit points, one wrong move can drain them nigh-instantly.
There're many sections that force you to shoot away walls bit by bit, which gets boring real fast. Making matters worse is that your helicopter's rate of fire is not consistant, it only fires the next round when the previous round has exited the screen or hit something. This, combined with the inability to maintain altitude, makes it very difficult to shoot the last few remaining bits of the wall blocking your path.
The music repeats itself in a loop which can become REALLY annoying after several minutes of play.
Going from screen to screen in the wrong place kills you, because there's no way to know what is the layout on the next screen, resulting in you flying unknowningly into an obstacle.
Unforgiving time limit. Making matters worse is that the timer is a glitchy mess, sometimes adding time to it and sometimes deducting time for no rhyme or reason.
The game freezes at the last screen upon completion, making it completely unbeatable. Yes, one of the hardest games in the world is literally impossible to beat due to a bug that makes the game crash at the very end.