Planet was an old arcade game released by Alca way back in 1979.
Asteroids marked a whole new era in space games. It was unlike any previous title. It was Atari's second vector game, and it was such an instant hit that they were forced to halt Lunar Lander production simply to try and keep up with the demand for Asteroids. As a matter of fact, the demand for Asteroids was so high that Alca was able to make their own PCB that would run a copy of Atari's revision A Asteroids program, and distribute the sucker all over Europe.
The game is rather simple. You pilot a small wedge shaped ship, and you begin play in the middle of an asteroid field. Large slow moving asteroids surround you, when shot they break into two medium sized asteroids, which will each break into three small, fast moving asteroids. Shooting the small asteroids makes them disappear. Your goal is simply to eliminate all the asteroids from the playing field, while avoiding anything that would cause you to lose a life (touching an asteroid, or getting shot by a flying saucer).
The playfield consists of a single screen (which wraps around in each direction). Your controls consist of five buttons which are "rotate right", "rotate left", "thrust", "fire", and "hyperspace", although some table versions of this game have been reported to contain joysticks. The ship moves rather realistically for a zero gravity craft, which means that it keeps moving even after you stop thrusting. This takes a little practice to get used to, but it really enhances gameplay, as it allows you to do fly-bys of asteroids and enemy ships.
There are two types of flying saucers that you might encounter. The first type is large, slow moving, and stupid. These are quite easy to shoot down. While the second type is small, moves quickly, and is more intelligent in its actions. These are the highest point value objects in the game, but are dangerous to approach.
There are three basic strategies that you might use while playing this game. The first is the newbie method. The idea behind the newbie method is that you do not use the thrust button at all, simply rotate in place, and use the hyperspace button if things get too thick. This method actually works for the first few levels, but is useless later on. The normal method is just to simply play the game, you won't rack up the highest score, but this is the most fun way to play. The final method is known as "lurking". While lurking you should shoot out all the asteroids except for one (or two), and position your ship in a corner. Soon small flying saucers will start appearing regularly, simply shoot these down for points (the best way to hit them is to wrap your shots around to the other side of the screen). This method assures an outrageous score (after some practice), but can get boring fairly quickly. It is also noteworthy to mention that all "Planet" machines contain the earliest revision of the Asteroids software, while almost all actual "Asteroids" machines contain a later revision designed to discourage lurking.
Most bootleg games were just shoddy circuit boards purchased from mail order houses located overseas, but not "Planet". Alca actually shipped entire machines. The Planet cabinet was a fairly generic wood grain jobber, with some mirror effects on the front.
The cocktail version was a little uncommon, it was rather unremarkable in appearance, and it was a Japanese style cocktail and not an American style one. Japanese style cocktails have metal legs, American style ones do not.
This game uses a black and white Hantarex X/Y monitor (a vector style monitor). This is unusual because it is a monitor that doesn't exist according to Hantarex. It appears they produced the monitor under the table, as they didn't want to officially custom produce a monitor for a bootleg game. Bootleg Star Castle units have been encountered with the same monitor.
Where to play
This game is Asteroids, so anywhere you can play Planet anywhere you can play Asteroids. Which could include the Mame emulator, your Atari 2600, or any one of the many clones out there.
These seem to be almost as common as actual Asteroids machines in Europe, although they are best avoided as the monitor is a real wild card, and there are not really any repair parts made for it.