Joust
Platform: Nintendo Entertainment System
Region: USA
Media: Cartridge
Controller: NES Gamepad
Genre: Platformer
Gametype: Licensed
Release Year: 1988
Developer: Williams
Publisher: HAL Laboratory
Players: 1 or 2 VS; CO-OP
_________________________

The player controls a knight armed with a lance, mounted on either an ostrich (player 1) or a stork (player 2), who battles waves of computer-controlled enemy knights mounted on giant buzzards. These knights have three different speed and agility levels. The game screen is static; its only features are five platforms hanging in mid-air (some wrapping around the screen), the ground, and a pit of lava beneath.

The simplicity of its controls are a factor in the game's wide appeal. A joystick moves left and right, and a "Flap" button flaps the mount's wings once. Pressing "Flap" in rapid succession will produce a gain in altitude until simulated gravity drags the mount downward.

Gameplay:

Each wave begins with enemy knights appearing on the screen at one of four "spawn points". The three types of knights, from weakest to toughest, are: Bounder (red, 500 points), Hunter (white, 750 points), and Shadow Lord (blue, 1,000 points). To destroy a knight and collect its point value, the player must collide with the knight while the player's lance is vertically higher than the knight's. If the player's lance is vertically lower, he or she loses a life and is awarded 50 points.

After destroying a knight, an egg will fall to the ground. The player must touch the egg to destroy it before the egg hatches to produce another, more powerful knight. This hatchling is harmless and may also be destroyed by touch prior to the knight mounting a new buzzard. The award for destroying eggs and hatchlings progresses with each one collected, from 250 to 1,000 points in 250-point increments. This progression starts anew upon the death of the player or the beginning of another wave. Players are further rewarded with 500 bobegins with enemy knights appearing on the screen at one of four "spawn points". 

A wave is cleared when the player destroys all enemy knights and eggs. Survival Waves reward a player who avoids death during the round with 3,000 bonus points. If too much time has elapsed during a wave, a pterodactyl will appear from one side of the screen and fly around until it either collides and kills the player, the player clears the wave, or the player destroys it by hitting the pterodactyl directly in the mouth with his lance, earning 1,000 points.

Two players can play Joust simultaneously, and each player earns points for destroying enemy knights as well as his human opponent (2,000 points). Cooperative play is possible by agreement, but accidental kills through collision remain possible. Completion of Team Waves award 3,000 bonus points each to players who successfully avoid killing one another. Gladiator Waves encourage players to kill each other by similarly offering 3,000 bonus points to the first player to do so.

During the first two waves flooring at the bottom of the screen covers a lava pit, which is uncovered on the third wave as the floor burns away. On the fourth and subsequent waves, a troll inhabits the lava pit; if any player or enemy knight flies too close to the lava, the troll's hand will emerge and tug the mount down toward the lava. Players can escape the troll's grip by repeatedly pressing the "Flap" button.

As waves progress, some platforms disappear, to be rejuvenated for "Egg Waves".

Every fifth wave is an "Egg Wave," which begins with a full screen of platforms (any that have disappeared are redrawn) already populated with eggs. These eggs hatch after a period of time, although it is possible for a player to destroy all eggs before any have hatched.

Programming bugs:

One flaw in the program's design, later touted by producers as a "hidden feature", gives players a strategic advantage. Two platforms are situated on the right side of the screen so that one slightly overhangs the other. If a player flies his or her mount so that its belly skims the lower platform such that its legs do not extend, the bird will then "belly flop" across the platform and illogically "squeeze" through the point where the two platforms meet, shooting out below the upper platform. Skilled players took advantage of this flaw to suddenly appear and land by surprise on an enemy knight or competing player. Game creator John Newcomer stated in interviews that this design flaw was so popular it was intentionally retained as a permanent feature of the game.

Early ROM revisions of the [arcade version of the] game presented a situation which a player could periodically exploit to accumulate an indefinite number of points with low risk. The player could maneuver an enemy knight too close to the lava, such that the lava troll would grip it, but not low enough that the troll would succeed in pulling it in, and not high enough that the enemy knight could escape. By doing so, the knight could not attack the player and the wave would never end. The player could then stand in the middle of the central platform to safely face oncoming pterodactyls, striking them in the mouth merely by standing still. Pterodactyls would appear at an increasing rate from different sides of the screen to be killed repeatedly, scoring large amounts of points toward extra lives. Arcade operators were not too pleased to see players exploit this bug.

http://en.wikipedia.org/wiki/Joust_(video_game)
