The Yars are the game's protagonist. They are essentially giant mutated House Flies in the far future. Throughout the game the Yars are battling mysterious and presumably evil aliens called Qotile. The Yars had three home planets before the Qotile attacked and destroyed one of them without warning. This set the Yars on a quest for revenge against the alien Qotile to protect their remaining two planets from harm.
You fly around the screen with the joystick and shoot your cannon with the fire button. The Yar will fire in the direction he is moving, making it not only possible to fire vertically but also horizontally. One of the reasons Yars' Revenge was so popular was because of its tight controls. The movement of the Yars is quick and allows diagonal movement. Because of this, Yars can easily outmaneuver enemies even if you can't outrun them.
The alien Qotile manuevers up and down the right side of the screen and will attack the Yars behind its shield. It pulses in a cyclic pattern of colors, and upon reaching a specific point in the cycle it turns into the lethal "Swirl" which will spin for a couple seconds before launching itself directly at the Yar. Initially, it only activates when the Quotile turns red, but as your score increases, it will activate three times in the color cycle.
In order to destroy the Qotile, you must eat away at or shoot the shield until you can get through to the Qotile to destroy it. There are two weapons at your disposal, an energy missile fired by the Yar itself (sometimes lovingly called a 'spitwad') which is useful for wearing down the shield, and the "Zorlon Cannon," an orbital cannon that is the only weapon that can destroy the Quotile. It is represented by a small scintillating rectangle on the left side of the screen which follows your vertical movement, in effect using the Yar itself as the targeting system. Once charged, the Zorlon Cannon can be fired by pressing the fire button, replacing the spitwad. If the Cannon touches either the Quotile or the Swirl, it is destroyed and you continue to the next level; otherwise it dissipates and the cannon charge is lost. Destroying the Swirl while it is in flight will net you an additional life.
There are a couple difficulty modes which affect the gameplay, primarily affecting the Zorlon Cannon. At the easiest difficulty, simply eating a few chunks of the Quotile's shield or touching the Quotile itself will charge the cannon, causing it to appear on the left side of the screen. When fired, it will disappear if it hits either the shield, taking a piece off of it, or the far right of the screen. The second variation causes the cannon to reflect if it strikes the shield, and will kill the Yar if it hits it on the return path.
The final variation, called 'Ultimate Yar' and by far the most fun, requires you to 'kiss' the left side of the playing field to charge the cannon after collecting energy. Five energy units are needed, and you get one for each shield chunk eaten, two for touching the Quotile, and four for catching the cannon after it reflects off the shield (which is not lethal in this mode). This means if you miss a gap in the shield, you can catch the cannon's blast and recharge the cannon quickly for a second try. Due to a programming flaw however, if you get 256 energy points it rolls over to zero.
The obstacles the Yars face include homing missiles and the Qotile's "swirl" attack. There is a "neutral zone" roughly in the middle of the screen. This zone provides protection from those pesky homing missiles but not from the other big threat, Qotile's "swirl" attack. As you progress through the game and rack up higher score, the Swirls not only get faster, but their attacks become more frequent and complex as well. Here is a chart showing the progression of the swirl attack based on current score:
|Score||Shield Color||Change In Swirl pattern|
|70,000||Blue||Swirls triple in frequency (Red, Blue, Green).|
Sometimes fire instantly.
|150,000||Gray||Swirls back to normal frequency, but they now |
change direction mid-flight.
|230,000||Pink||Three swirls again, with mid-flight direction changes. |
They sometimes fire instantly.
Yars are also unable to attack while in the neutral zone, so it's not somewhere you want to hang out all the time. Levels become increasingly fast as you move from stage to stage in order to increase difficulty, but there is no final level. The game will continue to produce levels until you run out of lives. The max score you can obtain in the game is 999,999 points. At that point you can consider yourself a master Yars' Revenge player, there's really nowhere to go from there. Here is another chart explaining how points can be scored:
| Shield cell hit by missile|| 69 points|
| Shield cell devoured by Yars|| 69 points and 100 bonus points|
| Qotile destroyed|| 1,000 points|
| Swirl destroyed in place|| 2,000 points|
| Swirl destroyed in air|| 6,000 points and a bonus ship (life)|
- The Neutral Zone and the explosion upon destroying the Quotile are machine code displayed as graphics for a quick-and-dirty effect.
In November 2010, Atari announced a game named after Yars' Revenge for PC, PS3 and Xbox 360. It was developed by Killspace Entertainment, and was released as a downloadable title on April 12, 2011. More reimagining than remake, the game is an on-rails shooter in which the player takes control of a heroine named Yar, who must fight off the enemy Qotile forces. Yar's Revenge features an aesthetic inspired by anime, with the developer having cited Studio Ghibli as an inspiration for the style.