"Uh… Evelyn, you know I'm not technical—can you explain that more clearly?" Ethan waved his hands, eager for clarification.
Evelyn flipped to the first page of his draft and pointed to the second paragraph. "Ethan, according to your design, Pac-Man is an endless maze-chase game, right?"
"Yes." Ethan nodded. "The basic idea: the player controls the protagonist to eat all the beans hidden in the maze while avoiding four pursuing ghosts. Clearing all the beans means you pass the level."
"The advanced mechanics are these: flashing 'power' beans appear — one in each corner. If the player eats one, they temporarily become immune to ghosts and can devour them. The ghosts, sensing danger, run away and slow down. And when a ghost is eaten, it returns to the house in the center to respawn.
Those three points are my ideas—am I asking for too much?"
Ethan was confident. "We're no longer doing simple circuit-board games now that we have the MOS 6502. As games get more complex, CPUs will inevitably drive game design. An arcade machine is practically a personal computer.
With the MOS 6502—comparable to the Motorola 6800—we've got a real hardware advantage. I've got creativity, tech, hardware—how could we lose?"
So when Evelyn said his design had a "big bug," "Ethan," she said, patient but firm, "I know you're eager, and I know you accept the MOS 6502 challenge. But your design violates a fundamental principle—the laws of binary."
"What?" Ethan didn't understand.
Evelyn pinched her forehead. "Let me explain simply: the carry rule in binary means that every two of something becomes one carried to the next higher bit."
"1 is just 1 in binary, but 2 isn't '2'—it's '10.' Then 3 is '11,' 4 is '100,' and so on. So, how high can the MOS 6502 actually count?
The answer is: a maximum of 255. Because it's an 8-bit processor.
The meaning of 8-bit is simple. Imagine eight little boxes in front of you, each of which can only be a 0 or a 1. The largest possible number is 1111 1111—which equals 255 in decimal.
Add one more 1, and the data overflows.
If one unit represents one level, this game can have at most 255 levels. There is no "infinity" like you wrote."
Evelyn flicked Ethan's draft with a snap of her fingers.
Ethan suddenly realized—it wasn't that the game couldn't be made. It was just that the infinite loop couldn't be made.
And to him… that was trivial! If the game can't be infinite, then don't make it infinite!
After all, no game in the world lets players go on forever. Breath of the Wild had people hooked for years, but once Tears of the Kingdom came out, it was instantly replaced.
The point is: as long as a game keeps players interested for a while, that's already the greatest success.
"This isn't a problem," Ethan said with a little grin. "If the MOS 6502 has limits, we'll just hit those limits. We'll make the best game we can—and let the rest take care of itself."
His tone was light, but Evelyn closed her eyes for a moment and then gave him a wry smile.
"Oh Ethan, do you have any idea how much work you just dumped on me?"
"Huh?"
"Two hundred and fifty-five levels, Ethan. It might take me a year just to design them all! And that's not even the worst part—the worst part is the four ghosts.
They each have their own style of chasing players. When you designed them, you thought you were a genius, right? And yes, it is clever—but this game is much harder to make than Snake.
To make each ghost choose its route randomly, we have to write four separate code blocks so they 'think' differently. And when the player eats a power pellet, those ghosts all have to run a detection code, switch from pursuit mode to panic mode, and move slower while fleeing…"
She let out a small sigh. "Do you know what kind of technology that requires?"
Evelyn smiled faintly. "To use the latest buzzword in science—this is artificial intelligence."
"What the—?!" Ethan nearly jumped out of his chair. He hadn't expected Pac-Man development to be this hard.
"AI?!" he asked, dumbfounded.
"Yeah. AI." Evelyn nodded, still smiling.
Ethan At that moment, he wasn't sure if this game was even possible. Pac-Man, powered by AI?
This was ridiculous. When he time-traveled, AI hadn't even been fully developed yet!
ChatGPT-4.0 was barely considered cutting-edge back then!
Just as Ethan was reeling, Evelyn waved the draft in front of his face. "Hey! Why are you zoning out already?"
Ethan spread his hands in mock defeat. "I'm just wondering if we have any backup plan for this project."
"Oh, Ethan" Evelyn chuckled, "don't tell me you don't believe in me?"
Her teasing tone made Ethan pause. "Aha?" he blinked. She had just been the one dumping all the bad news on him—and now she was laughing?
"You really can do this?" he asked, still a bit doubtful.
"Let's give it a try," Evelyn said, not committing completely. But then she added, quoting his own words back at him:
"As you said, we'll do the best we can—and leave the rest to the world."
It didn't seem like Evelyn wanted to continue with the boring technical discussion—rather, it was as if she had just found a brand-new toy.
Cheering herself up with a deliberately upbeat tone, she stood up, waved the scratch paper, and urged Ethan excitedly:
"Go! Go! Let's make a game! And Ethan—don't even think about running away this time! You're not allowed to go anywhere until we finish this game!"
She glared at him, though betrayed a smile.
"It's only been half a year since we made Snake, right? And you've already thrown me a problem this big? I really should thank you!
This time, I'm going to make sure you understand just how hard it is to make a game—so that next time, you'll think twice before dumping something even more difficult on me!"
Notes:
① Pac-Man really does have an upper limit, for the exact reason described above—the CPU limitation. On Pac-Man's 30th anniversary, Google even recreated this quirk in its doodle version: when you reach Level 255, the screen glitches out, and the original game would actually crash.
② Pac-Man is considered the originator of game AI and is still used as a benchmark for AI autonomous learning programming. Companies like Facebook, NVIDIA, OpenAI, and Microsoft all use Pac-Man to test AI capabilities. The game is not only culturally groundbreaking but also scientifically significant.
③ In real life, Pac-Man's creator, Toru Iwatani, led a team of nine developers who spent 17 months making the game.
At the time, most games took only about four months to produce. The extra time was because Iwatani wanted to make the game fun—if all four ghosts followed the same path, players could clear the levels too easily.
So he insisted on giving each ghost a unique pathfinding style. At that time, few people on the team—or even in the country—knew what "AI" was, since the concept was only circulating in American tech circles at Carnegie Mellon, Stanford, MIT, Harvard, and a handful of other research-heavy universities.
The team had to figure things out as they went, writing code by trial and error. Fortunately, they succeeded.