Defender (Arcade)

Defender (Arcade)

8/10 DifficultyMultiple Playthroughs30-50 Hours

Developed by WCopelandRAScript

About the Author

Hi! I’m Wes, the author of the RetroAchievements set for Defender. My fascination with this iconic game began in my childhood, when my father purchased a well-maintained arcade cabinet from a local dentist. He’d play Defender to unwind after a long day at work, and together, we’d spend hours enjoying the game to the beats of classic 80s hits. We kept things engaging by creating various challenges, like seeing who could survive on one life through an entire song or limiting ourselves to only 5 lives and 5 smart bombs.

As time went on, our skills and scores improved, and during my college years, I finally surpassed the million-point mark. This achievement sparked my interest in competitive arcade gaming, leading me to participate in Donkey Kong high score competitions. Although I’m grateful for my experiences with Donkey Kong, Defender will always hold a special place in my heart. I hope you find this guide helpful and that it ignites the same passion for this classic game in you.

Our family's Defender machine, resting in our computer lab.


Defender is a groundbreaking arcade game developed in 1980 by Eugene Jarvis and Larry DeMar and published in 1981 by Williams Electronics. It stands as an iconic side-scrolling shooter that captivated players with its challenging gameplay, remarkable complexity, and innovative mechanics. In fact, its difficulty and advanced controls even attracted the attention of Air Force pilots, who used the game for supplementary training. As you explore the RetroAchievements set for Defender, prepare to embrace the excitement of this timeless and challenging classic.

In Defender, you pilot a spaceship tasked with defending humanoids from alien invaders across a horizontally-scrolling terrain. Featuring a unique radar screen and the ability to thrust in both directions, Defender brought an unprecedented level of control and strategy to the gaming world.

This game comprises of multiple waves of increasing difficulty, with varied alien adversaries attempting to abduct the humanoids scattered across the landscape. Your mission is to protect them by eliminating the alien threat while avoiding collisions and hostile fire. Strategic use of your ship’s arsenal, including the powerful smart bomb, is essential for success.

The intense action, steep learning curve, and intricate controls make Defender an undeniably challenging experience. However, mastering its gameplay is an incredibly rewarding accomplishment, akin to learning a dead language. By the end of this guide, I hope to empower you with the skills and knowledge needed to conquer the alien invasion and defend the humanoids with confidence.

Remember, practice makes perfect, and with dedication, you’ll soon be able to overcome even the toughest waves of alien attackers and understand why this game was considered a hand-eye-coordination training tool for elite pilots in the U.S. military.

“Donkey Kong, Pac-Man, Ms. Pac-Man, Galaga, and Defender … these are the games that caught the public eye. These are the games people cared about. And so, if you want to be known as being world-class, you’ve got to master one of these games.” — The King of Kong: A Fistful of Quarters (2007)

Gameplay Mechanics and Tips

There is a lot of depth in the gameplay mechanics of Defender. As soon as you learn the game’s rules, you can start learning how to exploit them.


You Are Defending Humanoids

This is why the game is called Defender. Your purpose is to not only survive the waves, but to protect your humanoids as you progress. You start with ten humanoids, and all ten regenerate at the beginning of every 5 waves (ie: the first regeneration occurs at Wave 5).

Humanoids can die in three different ways:

  • When they’re captured by a lander and taken to the top of the screen.
  • When they’re dropped by a lander.
  • When you accidentally shoot them.

When you lose all your humanoids, the planet explodes and you enter “free-space” mode, where all the enemies are incredibly more difficult and aggressive. Successfully playing in free-space mode requires special training and tactics. As a result, most games end very quickly, within seconds, when entering free-space mode.

A humanoid being killed by a lander.

Saving a humanoid from certain death.

Force Yourself to Watch the Scanner

One secret to getting really good at Defender very quickly is to force yourself to not even watch the main play area. Just practice playing while watching only the scanner at the top of the screen. The best Defender players in the world are watching the scanner roughly 80% of the time. Given the expansive map, it is absolutely critical to have map awareness (and map control). The only way to learn that ability is by focusing on the scanner.

A Wave 1 clear by only looking at the scanner! Do this a bit and you'll be a pro in no time.

Don’t Play for Precision

The game will attempt to process a shot every time you press the Fire button. “Spray and Pray” is a viable tactic and one you should grow accustomed to. Defender will richly reward you if you adopt a playstyle of unbridled speed and aggression. There is a time and place for more measured and precise shots (such as saving humanoids from landers), but those times are few and far between.

Notice in the video clip below that while spamming the Fire button, I also spam quick presses of up and down. This causes shots to fan outwards, meaning I need to be less precise to land more kills.

Spamming the Fire button while pacing up and down will get you far.

Use Smart Bombs Effectively

The smart bomb button is one of Defender’s most important features. When you use a smart bomb, every enemy on the screen instantly dies. You start the game with 3 and will be awarded a new smart bomb (and life) every 10,000 points until you Game Over.

Be cognizant of your smart bomb use. They are a precious resource, and you don’t want to waste them! But what does “waste them” even mean?

  • Unless it’s a matter of life and death of a humanoid(s), don’t use a smart bomb to kill three or fewer enemies at once. You want big kills, not tiny kills.
  • Don’t forget about opportunity cost: when you Game Over, try not to have a single smart bomb remaining. An unused smart bomb is a wasted smart bomb.

The best place to use smart bombs is right at the beginning of waves, starting at Wave 3. You will spawn near some pods, and you want to smart bomb them all simultaneously. This very often instantly awards an extra life and another smart bomb.

The best place to use smart bombs is at the beginning of Wave 3+ against multiple pods.

The Baiters are the Timer

Unlike many games of the period, Defender has no explicit timer. Instead, super-challenging enemies called baiters spawn if you take too long during a wave. This usually spirals out of control, as baiters continue to spawn faster and faster until you die.

Baiters left unabated will eventually become an insurmountable challenge.


How to Reliably Kill Mutants

The secret to killing mutants is to let them get behind you, then quickly turn around and kill them. The worst way to fight mutants is directly head-on.

A basic demonstration of the mutant-killing technique.

The technique can even be used to kill multiple mutants at once.

How to Reliably Kill Bombers

You can kill bombers with a similar approach that you use to kill mutants. Never chase bombers from behind - their movement pattern and speed makes them very difficult to shoot in this manner. The best way to kill bombers is to jet in front of them, then quickly turn around and blast them head-on.

Kill bombers by racing in front of them and turning around to shoot.

How to Reliably Kill Baiters

When you first encounter baiters, it will probably seem like an insurmountable challenge to be able to dispose of them. However, there is a secret that makes managing them much more reasonable. When you realize a baiter is spawning, immediately let go of the Thrust button (stop moving). Baiters will initially try to match your speed when they first appear, so by decreasing your speed, you have a short window where you can outmaneuver them.

Use the speed-matching technique to kill baiters.

How to Abuse the Game’s Hardware and Slow Down Time

Defender’s hardware was ultimately limited by the restraints of the time, and you can abuse and exploit this to make the game easier. When you are holding an carrying humanoids, the game is constantly calculating what position the humanoids should be in on the screen for every frame of your movement. This is a very expensive calculation, and if you are holding multiple humanoids you can quite literally bring the machine to a crawl. In fact, dropping ten humanoids simultaneously will freeze the game.

If things are too fast-paced, try to deliberately hold three or more humanoids. You will find you can zip across the map much faster than landers can carry humanoids to their death.

Slow down time by holding multiple humanoids.

How to Survive Free-space

There is a trick you can abuse to make your time spent in free-space mode easier. There is actually an invisible vertical line on the map that sits at the point the screen technically wraps in the game’s code. Mutants cannot cross this line, and they will instantly reverse. Because of this, you can exploit their movements and actually push mutants away from you when you feel too much pressure. You just need to identify where the invisible line is.

Try to find the invisible line when in free-space mode, then abuse the mutants' movement.


Progression Achievements

First Flight [5 Points]
Clear Wave 1

Skyward Sentry [5 Points]
Clear Wave 2

Star Patrol [5 Points]
Clear Wave 3

Aerial Adept [10 Points]
Clear Wave 4

Cosmic Captain [10 Points]
Clear Wave 5

Galactic Gatekeeper [10 Points]
Clear Wave 6

Stellar Sentinel [25 Points]
Clear Wave 7

Unfortunately, there is no silver bullet that will carry you through the various waves of Defender. You will need to study all of the tips and strategies in the previous sections to be able to progress through the waves and make it this far. With time and practice, you will get better and better.

The best way to get good fast is to force yourself to play by only watching the scanner.

Challenge Achievements

Flawless First Flight [5 Points]
Clear Wave 1 on your first life

Flawless Skyward Sentry [10 Points]
Clear Wave 2 on your first life

Flawless Star Patrol [10 Points]
Clear Wave 3 on your first life

Flawless Aerial Adept [25 Points]
Clear Wave 4 on your first life

Flawless Cosmic Captain [25 Points]
Clear Wave 5 on your first life

Remember to use your smart bombs effectively and do not allow any to go to waste during these deathless runs. That means ensure they’re all exhausted before the possibility of your first death - it doesn’t matter if you bring them with you for your second life.

Full House I [5 Points]
Clear Wave 1 with 10 humanoids remaining

Full House II [5 Points]
Clear Wave 2 with 10 humanoids remaining

Full House III [10 Points]
Clear Wave 3 with 10 humanoids remaining

Full House IV [10 Points]
Clear Wave 4 with 10 humanoids remaining

Full House V [25 Points]
Clear Wave 5 with 10 humanoids remaining

Note that Full House V can actually be earned independently of the first four achievements in this series. This is due to all of your humanoids regenerating on Wave 5. You will always enter Wave 5 with 10 humanoids left, you just need to keep them alive.

There are two tricks you can use to make these achievements easier:

  • Don’t put your rescued humanoids back on the ground. Keep carrying them to not only protect them, but to slow down time.
  • If there is a humanoid about to die from a lander that you’re unable to reach, intentionally suicide. On your next life, the humanoid will still be alive, even if it was being held by a lander at the time of your death.

Continuity Cache [10 Points]
Hold more than five lives in reserve

Once you have five lives in reserve and earn a sixth, the game will still give you the life, but it won’t appear on the top left of the screen anymore.

Space Invaders Tribute [10 Points]
Clear Wave 1 without pressing Up or Down

One trick to make this achievement easier is to use the Hyperspace button. Hyperspace causes you to teleport to a randomly-selected spot on the map, which includes a different position along the screen’s Y-axis. Note that Hyperspace also has a 50% chance of killing you, but achievement doesn’t need to be done on a single life.

No-Bomb Novice [5 Points]
Clear Wave 1 without ever using a smart bomb during the playthrough

No-Bomb Newcomer [5 Points]
Clear Wave 2 without ever using a smart bomb during the playthrough

No-Bomb Notable [10 Points]
Clear Wave 3 without ever using a smart bomb during the playthrough

No-Bomb Natural [25 Points]
Clear Wave 4 without ever using a smart bomb during the playthrough

Your biggest hurdle with these achievements will be handling the pods and swarmers that emerge from them without smart bombs. The best way to deal with swarmers is to kill as many as possible by spamming the fire button as soon as they start coming out of a pod. To hunt them down, don’t face them head-to-head. Instead, chase behind them and try to match their speed while shooting at them.

Straight Shooter I [5 Points]
Clear Wave 1 without ever using reverse

Straight Shooter II [5 Points]
Clear Wave 2 without ever using reverse during the playthrough

Minimalist Marksman [10 Points]
Clear Wave 1 without pressing Fire more than 5 times

To earn this achievement, you will need a few well-placed smart bomb uses. Wait until many enemies are clustered on the screen, then kill them using one of your smart bombs.

Baiter-Free Breeze [10 Points]
Reach Wave 3 with no baiters ever spawning

This will all come down to how quickly you can reach Wave 3. If you play aggressively, it should be possible to reach Wave 3 with no baiters ever spawning. Consider this practice for the “Beat the Clock” achievement.

Edge of Extinction I [5 Points]
Begin Wave 2 with one humanoid remaining, and ensure it survives until reaching Wave 3

Edge of Extinction II [10 Points]
Begin Wave 2 with one humanoid remaining, and ensure it survives until reaching Wave 4

Edge of Extinction III [10 Points]
Begin Wave 3 with one humanoid remaining, and ensure it survives until reaching Wave 5

This is easier than it sounds. There are two approaches you can take:

  • Camp the humanoid and defend it, not allowing anything to come near.
  • Deliberately allow a lander to pick up the humanoid, then kill the lander and grab the humanoid as it falls, never setting it back on the ground. Landers will now float aimlessly with no objective.

Free-space Explorer [25 Points]
Begin Wave 2 with no humanoids remaining, and reach Wave 5

The most critical thing to understand when it comes to earning this achievement is how to abuse the invisible line while in free-space mode. You’ll want to combine this with maximizing your smart bombs to destroy as many mutants as possible.

Technique Achievements

Life Saver I [3 Points]
Catch a humanoid

Life Saver II [2 Points]
Return a humanoid to the ground

Life Saver I & Life Saver II can be earned in rapid succession.

Time-based Achievements

One-Minute Warrior [5 Points]
Survive for longer than one minute on your first life

Two-Minute Warrior [10 Points]
Survive for longer than two minutes on your first life

Three-Minute Warrior [25 Points]
Survive for longer than three minutes on your first life

These achievements will take a lot of practice, and you will need to combine multiple tactics that are discussed earlier in this guide. There is one trick you may find helpful: when you’re down to one enemy left in a wave, delay killing them for as long as possible. Hunt a baiter or two if that’s what it takes. This will buy you valuable seconds that can help you unlock these achievements.

Beat the Clock [10 Points]
Reach Wave 4 within two minutes and fifteen seconds

This will truly test your ability to approach Defender with an aggressive playstyle. Even with deaths, you should be able to achieve this with such a playstyle. Take a look at the video below:

End of the Road

Celestial Champion [50 Points]
Clear Wave 8

The significance of this wave is it is the game’s maximum difficulty threshold. After clearing this wave, you will notice that Wave 9 returns to using the same blue border from Wave 1. It never gets any tougher from here!

Four-Minute Warrior [50 Points]
Survive for longer than four minutes on your first life

As suggested earlier in the other time-based achievements, you want to buy as much time as possible during the downtime that occurs near the end of stages. Practice killing baiters as they spawn. If you can manage that, there is no urge to actually progress.

Unstoppable Force [50 Points]
Score 200,000 points

A true test of skill! If you are able to break the 200,000 point barrier, you’re probably only one more step on the ladder away from being able to play to 1,000,000 points. 200,000 points will occur several waves after Wave 8. Depending on your playstyle, this threshold should be reached somewhere between Waves 12 and 14.

Hell in Space [100 Points]
Begin Wave 2 with no humanoids remaining, and reach Wave 5 without ever using a smart bomb

The hardest achievement in the game by far, and one you should not attempt until you unlock everything else. To unlock this, you must have mastered literally everything else in this guide. This will take an incredible amount of skill and just a pinch of luck. Be sure to abuse the hidden vertical line, follow the scanner as appropriate, and don’t be overwhelmed by baiters while doing so. Pods and swarmers are also exceptionally dangerous. Keep in mind that the number of swarmers which spawn from a pod is random. Therefore, it is certainly possible to have bad games where an overwhelming number of swarmers appear. Don’t get discouraged! Just keep grinding, and with enough practice you will eventually unlock this and master the game.