Choplifter

Choplifter is a 1982 Apple II game developed by Dan Gorlin and published by Brøderbund. It was ported to other home computers and, in 1985, Sega released a coin-operated arcade game version. While many arcade games have been ported to home computers and consumer consoles, Choplifter was one of the few games (Lode Runner is another) to take the reverse route: first appearing on a home system and being ported to the arcade.

Overview
In Choplifter, the player assumes the role of a combat helicopter pilot. The player attempts to save hostages being held in prisoner of war camps in territory ruled by the evil Bungeling Empire. The player must collect the hostages and transport them safely to the nearby friendly base, all the while fighting off hostile tanks and other enemy combatants. According to the backstory, the helicopter parts were smuggled into the country described as "mail sorting equipment."

Although the Iran hostage crisis ended the year before the game was released, Gorlin has stated "the tie-in with current events was something that never really crossed my mind until we published."

Description
The helicopter (named "Hawk-Z" in the Master System version manual) can face three directions: left, right, or forward (facing the player). It may shoot at enemies in any of these directions and need not fly in the same direction it is facing. The forward-facing mode is used primarily to shoot tanks. Care must also be taken to both protect the hostages from enemy fire and not accidentally shoot them oneself.

The player rescues the prisoners by first shooting one of the hostage buildings to release them, landing to allow the prisoners to board the sortie, and returning them to the player's starting point. Each building holds 16 hostages, and 20 passengers can be carried at a time, so several trips must be made. When the chopper is full, no more hostages will attempt to board; they will wave the helicopter off and wait (hopefully) for its return. Usually, each trip back is more risky than the previous one since the enemy is alerted and has deployed a counter-attack.

If the player lands directly on top of a hostage, or completely blocks the building exit, the hostage(s) will be killed. In the Apple II and Atari 7800 versions, hostages will also die if the vehicle is not landed correctly (it is slightly tilted), being crushed as they attempt to board the chopper. While grounded, the helicopter may be attacked by enemy tanks, which it can shoot at only by returning to the air. Also, the enemy scrambles jet fighters which can attack the vehicle in the air with air-to-air missiles or on the ground with bombs.

Platforms
Choplifter was ported to many other home systems of the era. These versions were ports of the original Apple II game, not the later arcade version. These systems include the Atari 5200, Atari 7800, Atari 8-bit family (and a graphically updated version for the Atari XEGS), ColecoVision, Commodore 64, Commodore VIC-20 and MSX. German publisher Ariolasoft published the European Commodore 64 version.

In 1986, ports of the arcade version back to home versions were developed for the Nintendo Entertainment System and Sega Master System. Not surprisingly, the arcade version and its ports are more colorful and intense than the Apple II version. It boasts more environments (desert, sea, caves and city) as opposed to the Apple's single desert environment. The arcade version is listed in the Killer List of Videogames Top 100 and one of the four best games in 1985.

Version differences
In the original Apple II game, play continues until all three helicopters are destroyed or all prisoners are either rescued or killed. There is no scoring system other than the counters at the top of the screen, which indicate how many of the 64 total hostages have been killed (red), how many are on board the helicopter (blue), and how many have been rescued (green). The best possible result is to rescue all the hostages, for which the game will award you a triple crown, Brøderbund's emblem. The Commodore 64 version is the same.

In the arcade version, a point system is used, giving points for enemies killed and hostages rescued. Furthermore, the arcade version has only eight hostages per building rather than 16. In order to move from one level to the next, the player must rescue at least 20 hostages (40 in the Sega Master System version). The arcade version also forces the player to restart a level if too many hostages are killed, but does not restore any helicopters lost. (In the Sega Master System version, this automatically ends the current game in progress.) Another difference in the arcade version is the addition of a Fuel Meter. This was essentially a time limit because there was only one way to replenish the meter—saving hostages.

The original game provides a safe zone around the player's launch area where the player was largely free from attack. A fence indicates the border between friendly and enemy territory. While the fence is still present in the arcade version, enemy jets will pursue the player's helicopter all the way to his landing pad.

In the original game, a new enemy is added with each trip the player makes. First, the player faces only tanks which are limited to attacking only when the helicopter has landed or is extremely close to the ground. The next trip introduces jet fighters that shoot missiles at the helicopter in the air and bomb it when it's on the ground. The last enemies are "air mines" which attempt to collide with the player's helicopter, and which on the fourth trip gain the ability to shoot. The arcade game has a larger variety of enemies which vary more according to each level's landscape rather than the number of trips the player has made. The most significant of these are anti-aircraft guns which make the arcade version much harder than the original. It retains the tanks and jet fighters, but does not include air mines which follow the player's helicopter. The arcade version also gives the ability, once the helicopter is shot down and while it is falling in flames, to make the hostages jump with parachutes by repeatedly pressing the 'turn' button, these hostages can be rescued again in subsequent sorties and will not count as dead hostages.

The original Apple version (and perhaps other platforms) contains what is arguably a bug: it is possible to create a situation in which the game cannot end. The hostages will run towards the helicopter when it lands. If the helicopter takes off before hostage can board, and lands closer to the base, the hostage will again run towards the helicopter. With repeated "hops," the hostage can be led back to the base; when led within the fence, the hostage will run straight into the base—however, that rescue is not counted. As a result, that hostage will never count as either a rescue or a death, and the game cannot end (except by the destruction of all the helicopters).

Reception and legacy
This game was fairly successful and popular, spawning two sequels: Choplifter II for the Nintendo Game Boy and Choplifter III for the Nintendo Game Boy and Super NES. On the Commodore 64 and the MSX, games related to Choplifter were Lode Runner and Raid on Bungeling Bay, all three games featuring the fictional Bungeling Empire.

In a review by Computer Gaming World, the graphics and animation were highly praised.

In popular culture
Choplifter is played by U.S. submarine crew members in Tom Clancy's book The Hunt for Red October, and the Sonar man aboard the USS Dallas, Jones, has the high score. In Mario's Picross, Easy Picross Level 6A is a helicopter similar in appearance to Choplifter. When the puzzle is solved, the caption describes the image as "Choplifter".