Summary

The author reminisces about their childhood experience with the 1986 shoot-em-up video game Zanac for the MSX home computer, which featured early artificial intelligence (AI) to adapt the game's difficulty based on the player's skill and actions.

Abstract

The article is a nostalgic reflection on the MSX game Zanac, which the author played extensively as a child in 1986. The game's use of artificial intelligence, referred to as ALC (Automatic Level of Difficulty Control), is highlighted as a unique feature that adjusted the enemy's strength and quantity according to the player's attack patterns and skill level. The author describes how they gradually uncovered the game's AI mechanics, which led to a deeper understanding and enjoyment of the game. They also contrast the dynamic experience provided by Zanac's AI with more modern games that often rely on predictable patterns and lack the same level of engagement. The article concludes with the author recommending Zanac as a must-play retro shooter and subtly promoting a cost-effective AI service, ZAI.chat, drawing a parallel between the game's AI and contemporary AI technology.

Opinions

The author views Zanac's AI as a groundbreaking feature for its time, significantly enhancing the game's replayability and challenge.
They believe that the game's adaptive difficulty made it feel like a new experience each time it was played.
The author suggests that Zanac's AI influenced their decision to study Cognitive Artificial Intelligence at university.
They express a preference for the unpredictability and adaptiveness of Zanac's AI over the static patterns found in many modern games.
The author values the strategic gameplay that Zanac's AI system encouraged, such as conserving ammunition and avoiding unnecessary combat.
They lament the loss of their childhood perception of AI as they learned more about the field in their university studies.
The author fondly remembers the sense of accomplishment from beating Zanac's AI and recommends the game to others who appreciate retro shooters.
They subtly promote ZAI.chat as a modern AI service that offers similar performance to ChatGPT Plus (GPT-4) but at a lower cost, implying that it captures the innovative spirit of Zanac's AI.

Prescription in 1986: Zanac. Artificial Intelligence in this retro shoot-em-up

I experienced the power of AI back in 1986 when I was about 10 years old. We owned an MSX home computer, and I am eternally thankful that I got my hands on my all-time-favourite shoot-em-up Zanac. Back then I played the game relentlessly. Sometimes I would sit down to win, or sometimes… I found out the game had Artificial Intelligence. Wow! Sometimes I would experiment with the AI.

Not this kind of AI. We’re not quite there yet in the eighties. Image by Thomas Meier from Pixabay

What did AI look like in 1986?

It took me numerous times to figure out the game was adapting to my playstyle. As I played and as I watched my brother play, I started noticing that our level progressions weren’t the same. Some playthroughs were a lot harder than previous ones. So I did whatever a 10-year old with all the time in the world would do: I’d play and play and play again to figure out the secrets of this game.

ZANAC uses ALC (Automatic Level of Difficulty Control function) which is programmed by AI (Artificial Intelligence). The strength and quantity of the enemy changes according to the pattern of attack and player’s skill level. The place where the enemy appears also varies game by game. This feature is unique to Zanac. So playing ZANAC the fastest, most advanced space game, is like playing a new game each time.

— from the Power Play Feature section of the Zanac’s manual

At first I didn’t know the game could adapt to my skill and attack patterns. A friend came over to play and pointed at the title screen:

“It’s not called Zanac. It’s Zanac A.I.”.

“Yeah, must be the ships’ type or something.”

We then set out to play, unknowingly ignoring a great hint at this games’ hidden gem.

Later I would ask my dad what A.I. meant. He really sparked a blazing fire in me talking about this wonderful new technology and how it would shape our future world. Now I was no longer playing a game. I actually felt part of the future.

Now, when friends would come over, I would do a lot better. I knew I should reserve bullets, avoid enemies that weren’t threatening me, and just dodge bullets. I tried telling any friend that came over to play, but

What’s the appeal in a shoot-em-up that doesn’t allow you to blast things?

Whenever I played Zanac, I would always be careful to kill the first enemy with a single bullet. If I was successful, it would drop an extra life. Otherwise, nothing.

The video below features a full playthrough of Valis77 beating Zanac. His skill is obvious in being able to beat the game with a single ship. I, however, cringe at the way he wastes bullets and seems to enjoy aggravating enemies:

Exclusive Power Play feature includes:

High rapid-fire rate increases the level of difficulty relative to the player’s and enemy’s skill level.

Each appearance of an object in the air increases the enemy’s strength.

A destruction of a fortress decreases the enemy’s strength. Failure to destroy the fortress results in an increase of the enemy’s strength.

These are a few ways in which the strength and quantity of the enemy is adjusted according to both the enemy’s and player’s level.

— from the Power Play Feature section of Zanac’s manual

Valis77’s gameplay isn’t concerned with the above characteristics of the game’s AI at all. How could you use the system to your advantage? The next video is uploaded by GMIX6809. He plays exactly as I would play:

See how the second player managed to get a sweet extra life? Unlike Valis77 I would definitely need it in later levels as my inner calm would be destroyed by the upbeat repetitive music (great, albeit very repetitive) and the waves and waves of enemies and bullets.

The first level was easy-going for me. In the consequent levels the enemies become harder and I was sure to make more mistakes, which made me either lose my ship or made me fire more bullets. Both increased my odds of not beating the end boss. As I’d progressed further into the game, I would stop experimenting and just enjoy the fast-paced scrolling adventure. I am happy to say I managed to beat the game a couple of times.

Overcoming fear of AI — a different strategy

In a typical shooter you are concerned with questions like: what is the next enemy pattern? Which powerup should I acquire before the next stage? Which enemies should I kill immediately? What is a safe zone to dodge bullets in the upcoming boss fight? With the AI handing you different struggles each play, those questions are still valid, but I concerned myself with more important questions:

How long can I survive without firing a bullet? What happens if I don’t take out the boss? Can I destroy it without taking out its turrets first? How close can I get safely to have a higher fire rate and better accuracy? Which enemies are best left alone? Which powerups drive the AI into a frenzy?

It’s not very intelligent for an Artificial Intelligence

In 1996 I enrolled into University for a degree in Cognitive Artificial Intelligence. I am unsure how much Zanac had to with making that choice, but I do know that I set up my Nokia 3310 with a Zanac-ringtone at about that time. I went as far as to search for a midi-file, edit it and convert it to something that the phone would accept. No one recognized it and that may be a reason for writing this story.

In an introductory class I learned that as the field of Artificial Intelligence progresses, our perception of what we think is truly (artificially) intelligent shifts.

At the time the computer Deep Blue won against Garri Kasparov in chess. Was this truly AI? We discussed how we felt: was it just plain brute force that made Deep Blue win? How about preprogrammed algorithms? Or were there some smart heuristics involved? Or a combination of these and other actual AI-techniques? All I remember taking away from that class is that I was no longer sure what I was studying.

Another takeaway was that while Zanac’s developers boasted to use AI in their game, it was probably just a very basic algorithm to determine difficulty. How I wish life wouldn’t just smash my childhood dreams.

Prescription: Zanac

Zanac delivered a different experience each time I popped my cassette in. When I play a modern game, I often find myself longing back for this level of effectiveness. Enemies using the same predictive pattern over and over again or followers die on you due to lack of common sense (yeah, I’m looking at you, Skyrim!). It usually just doesn’t fill you with the experience you are hoping for.

Zanac thrilled me to no end. After I had beaten it, I was rewarded with the end credits. My ship glides over the planet, now rid of enemies. I’d sink back in my chair and enjoy the slight variation of the game’s musical score. The feeling that my own organic ‘intelligence’ self just managed to beat an AI was marvelous.

Every now and then I want to find an MSX-emulator to experience the feeling of beating an AI again. I sometimes do. It feels great to shoot the first bad guy with a single bullet. A few minutes in I find that my skills are lacking and that a 1986 bullet hell game is too challenging for me. As it appears, there is no AI required to make me fail. All that aside, I will still definitely prescribe Zanac for anyone longing for a good retro-shooter.