It's Phoenix meets Gorf. How could that being anything but fun?
Sky Fox is a vertical shooter that has enemies that like to vacillate back and forth (like Phoenix) and come at you in distinctly different stages (like Gorf).
You control your ship with the joystick and two fire buttons. One for your normal weapon and one for your more powerful/rapid-fire weapon. There is a big difference between the two. The main weapon can only fire one missile at once, it's slow and plodding. The rapid/multi fire is great. You can fire as often as you'd like and at times there are two or three missiles fired simultaneously. The problem is that this weapon has a limited number of shots. There is a count at the bottom of the screen called "power". That is how many shots you have left - but not exactly. You see, when your power count is greater than 100, you shoot 3 missiles at once (for each button press) - that's cool, except it subtracts three from your supply. So, if it was 150, you push fire once and it's at 147. Once the power drops below 100, you only fire two simultaneously, and it subtracts two from your count. Under 50, you simply fire one at a time, but you can still fire rapidly and have as many in the air at the same time as you want. Run out and that's it until you replenish. The way you replenish is by capturing the power-up "P" that floats down after defeating certain enemies.
The enemies are cool. Dragons are the first you encounter and they slink and curve all around - you have to hit them in the head. On the second level, the baddies sets up in formation, a little like Galaxian. Some of the enemies are Space Chicks who are only vulnerable when they open up their coat (I'm not making this up). Yes they have clothes underneath (bathing suit?) and that's when you can kill them. Hit them when their coat is closed and you simply drive them back up the screen towards the top. Cool. Then, more dragon/birds and some spaceships and some asteroids. Then, like Gorf, it's lather, rinse, repeat.
Like all good games, you get rewards at the end of the cycle based on time completed and hit rate in firing.
The graphics are not special, but fit well with the game that looks a little more old school than it is (1987). The shooting action, jittery enemies and thoughtful management of your better weapon make Sky Fox a good time.