An included comic book sets up the plot: Yars began as ordinary Earth houseflies, who hitched a ride aboard a human spacecraft on a mission to the Razak solar system. The mission ended in catastrophe, but the flies escaped and mutated into super-beings that built advanced civilizations on three of the Razak system's planets. To protect themselves, they created a BFG called the Zorlon Cannon. But before the cannon was finished, an enemy called the Qotile attacked and destroyed one of the planets. So now the Yars must get their revenge by destroying the Qotile.
The game itself started as a port of Star Castle, and still has some of its gameplay elements, such as the main enemy hiding behind a shield, and a smaller enemy chasing you around. You play a Yar, a giant fly that shoots energy missiles. On the right side of the screen is the Qotile, surrounded by a shield. You can shoot away the shield, or come right up to it and eat it. Once you have destroyed enough of the shield, you call in the Zorlon Cannon. Different variations of the game have different methods for calling the cannon. Once you have called the cannon, you position it by moving the Yar up or down. The Qotile is always moving up or down, and the Zorlon fires a Painfully Slow Projectile, so you have to Lead the Target carefully. Then you fire it, and get out of the way or you will kill yourself with your own cannon.
The Qotile cannot directly harm younote , but it does launch a Destroyer Missile that chases you around. From time to time, the Qotile will also turn into a Swirl, that fires at you at high speed. In the center of the screen is a Neutral Zone, where you are safe from the Destroyer Missile, but not the Swirl (being that it is a planet-annihilating weapon), and where you cannot fire. And that includes not being able to fire the Zorlon Cannon.
The game is endless, and the only objective is Scoring Points. More points are awarded for hitting the Swirl with the Zorlon Cannon than hitting the Qotile, and more still are earned for hitting a Swirl in mid-flight (not easy considering that both the Swirl and your own Zorlon Cannon can kill you).
Alternating levels have different shield types. Higher difficulty levels cause the Qotile to become the Swirl more often. But the Red Swirl is always the swiftest and deadliest.
Yars' Revenge provides examples of:
- All There in the Manual: The original game included a mini-comic entitled "The Qotile Ultimatum" that explains the story, and exactly why the Yars were gunning for revenge. It suffers from an extreme case of As You Know syndrome, however.
- BFG: The Zorlon Cannon. This becomes Super Weapon Surprise as the Yars use it to blast the Qotile to pieces after they destroy one of the Yar worlds.
- Boss Game: The whole game is the Yars vs variations of the Qotile, there are no minor enemies, there are no levels to traverse, no mini games.
- Deflector Shields: The Qotile deploys several different kinds, all of which are edible, no less (due to the Yars being able to eat any substance). Your energy missile also chips away at the shield quite quickly, but the Zorlon missile will just take a single cell out of it and, in some game variations, bounce off (and likely into you - though, again, depending on the game variation this could be a bad or a good thing).
- Difficulty Levels: Four, with one and two player variations: an easy game (with slow missiles and Swirls), a medium game (with faster missiles and Swirls), a hard game (same as medium, but the Zorlon Cannon bounces off the Qotile's shield and can kill you on the rebound), and Ultimate Yars (same as hard, but it requires you build up a resource called "Trons" to summon the Zorlon cannon; getting hit by the Zorlon Cannon when it bounces off the shield gives you Trons in this variation).
- Easter Egg: If you kill a Swirl in mid-air, a black vertical line appears where the Swirl died. It's a Warp Zone, and if you move along it at just the right time and place, it takes you to an ending screen with programmer Howard Scott Warshaw's initials, spelled both forwards and backwards ("HSWWSH"). Unfortunately, it's also an automatic "Game Over", since it freezes on that screen until you reset the game.
- Energy Weapons: The Yars' shots are described as "energy missiles".
- Excuse Plot: After you take the Yars' revenge you have to do it again, and again, and again...it's an Endless Game that just makes the scenario different or more difficult each time...so rack up that score!
- Extreme Omnivore: As noted in the pack-in comic, Yars can eat any substance and convert it to energy missiles.
- Hoist by His Own Petard: You, if you don't get out of the way of the cannon projectile.
- Homing Projectile: The Destroyer Missles follow the Yar relentlessly. And they get very fast as the game goes on.
- Insectoid Aliens: Justified in that they're Earth insects that got mutated into intelligent beings while in space.
- Justified Extra Lives: Always another Yar to send out there.
- Lead the Target: Shooting the Qotile with the Zorlon Cannon.
- One Bullet at a Time: The Zorlon Cannon shoots one shot at a time and no more than destroyer missile can be on screen.
- One-Hit-Point Wonder: Your Yars die from one hit from anything, including your own Zorlon Cannon.
- Painfully Slow Projectile: The Zorlon Cannon, which works both for you and against you. For you, in that it gives you time to get out of the way; against you, in that you have to set up a shot against a moving target.
- Scoring Points: The main point is to go on as long as you can, score as many points as you can and see if you scored more than your friends.
- Shoot 'em Up: A weird take on the classic Shielded Core Boss of the genre.
- Shout-Out: To Atari CEO Ray Kassar. Yar and Razak are Ray's name spelled backwards. Also the Neutral Zone, and Trons, which are used in some variations to call the Cannon.
- Spiritual Successor: to Star Castle. Yars' Revenge originally started out as a direct port of Star Castle, but it changed a lot during development.
- Wrap Around: Vertical only, you have to cross the neutral zone the hard way but can reappear on any side of it with impunity.
- Writing Around Trademarks: As noted above, this was supposed to be a port of Star Castle when the licensing deal fell through. Howard Scott Warshaw decided to rework it into an original game.
The reimagining (called "Yar's" note Revenge) provides examples of:
- Bare Your Midriff: Yar's armor doesn't cover her stomach
- Blood Knight: Yar qualifies big time. Seen most clearly in stages 2 and 3.
- Stage 2: The Qotile unit commander, wanting to make sure the Ankine queen is destroyed, orders the charging of the Zorlon Cannon, and tells Yar to retreat and leave the Qotile superweapon to kill the queen. Yar refuses, wanting to kill her herself. Cue the Boss Battle!
- Stage 3: Yar reluctantly runs away or hides when Bar-Yargler tells her to stay away from the Qotile dreadnoughts, but ultimately grows fed up and, when one of them notices her, she attacks it with all she has. Cue Boss Battle!
- Breath Weapon: General Triatoma and Zyron can shoot bursts of glowing death
- Cores-and-Turrets Boss: MOG-01, who has a picture of the original game's Qotile on it.
- Deadpan Snarker: Bar-Yargler is very good at snarking. Yar picks up the habit herself while talking to him, though she can't match his zingers.
- Deflector Shields: In the backstory it is the Yars who use one of these, rather than the Qotile. Yar herself can bring up a rainbow shield to restore her health, though it has limited energy. Also, the Ankine bosses can bring up such shields.
- A Dog Named "Dog": Yar is a member of a race known as the Yars.
- Fantastic Slur: Ankine are called "nectar drinkers".
- Fighting Your Friend: Zyron and Yar used to be but the former becomes a boss battle for the latter.
- Frickin' Laser Beams: Queen Goptrii and Zyron have lasers that you have to dodge by watching where they scrape across the screen, similar to Sin and Punishment: Star Successor. The main weapons are also called "pulse lasers", Qotile are red, Yar are blue.
- Homing Projectile: This time it is Yar who lock on to the enemy and shoot missiles. She can hold up to twelve at a time. She can also acquire a temporary helper that seeks out enemies.
- Humanoid Aliens: Yars are still mutant Earth insects, but they look like 4-armed humans with wings and antennae. The Ankine and the non Yar Qotile slaves are still Insectoid Aliens
- Mind over Matter: General Triatoma can cause rocks to float towards you over matter rocks
- Mythology Gag: The MOG-01 computer displays the symbol used to represent the Quotile in the original Atari game.
- In Name Only: There is some stuff from the original that remains here (namely, there are the Yars, the Qotile, the Zorlon Cannon, the Yar homeworld is still called Razak), but most of it has been reimagined, including the gameplay, to the point that you wouldn't think that the original game and this one had much of a link between each other.
- Macross Missile Massacre: Tarsus starts out shooting missiles straight up, where you aren't at, but then they swerve towards your position.
- Magnetic Weapon: Yar has a personal rail gun. It's a Weapon of X-Slaying against arachnids.
- Mid-Season Upgrade: Yar gets a new armor in the beginning of Stage 3. Later on, she also gets the Zorlon Cannon.
- Not So Stoic: Yar is the stoic until she loses the armor the game starts you in
- Roaring Rampage of Revenge: As suggested by the title, Yar is out for revenge against the Ankine for breaking her armor, then against the Qotile for suppressing her memories.
- Shock and Awe: One of your potential helpers will shoot down enemy projectiles with lightning
- Slave Race: Yar's race was once independent, but then the Qotile came to Razak and waged war against them. By the end of the war, the Yars that remained (Including the protagonist) were brainwashed into believing they were subservient to the Qotile.
- Smart Bomb: The Zorlon Cannon removes all enemies from the screen. The Qotile sent spies to steal it from the Yars but you eventually get it back.
- Teleporters and Transporters: General Triatoma can teleport short distances
- Third-Person Person: A variation with Yar who refers to herself as "this-one" (sic); also the villains.
- Training from Hell: MOG-01 tests warriors with live ammunition