Fable is extremely good at writing original NES games in assembly. Here it designed an original game graphics, soundtrack, everything from scratch, and it'd actually run within the constraints of a real cartridge. Wild.

It also made this other really fun game called Warp Kid, a platformer with portal guns, still within NES limitations.

I don't think people get how insane this is. It would have to have knowledge of very specific 6502/2A03 code, PPU gfx and APU sound..all the memory maps... cartridge mappers... timing... ROM/RAM limits..and trained so well on it that it can pulls it all together to make it playable

yes

wait, it composed the chiptune too? insane

Everything! Can share the full chat. This was one shot on high effort.

Great at C code for SNES as well. It fully ported my game "Rotatron" to a killer SNES version. Original is here:

Could be a fun movie script where an obsessed teenager somehow gets access to this technology back in 1986 (via extra-dimensional portal or something) and uses it in secret to create a one-man gaming empire. Only to be undone by a pesky little sibling or envious hater.

Original game? That's Flappy Bird.

Hard to say it’s not AGI when it’s replicating entire video game studios from 30 years ago

That's pretty amazing! I'm surprised there's sufficient training data out there for coding such old NES games.

It can also do SNES!

kinda love that it composed the chiptune within the apu's fixed channels. you'd have to actually know the hardware to respect that constraint, and it one-shot the whole thing

I gonna try this with Gameboy Color and test it on my mod retro.

It would be so cool if it could just decomp all the NES games to PC ports. LED screens are the biggest drawback to retro consoles IMO. Being able to play retro games at 240 and 480FPS would close that gap and bring them close to CRT like motion clarity. This is super cool!

Removing the need to learn machine language is going to blow open the flood gates of new incredible human and AI art.

@dested

That's legit impressive—constraint-aware generation at the assembly level is a far more meaningful benchmark than chat or code completions. Would love to see the cycle count and ROM size compared to human-written NES classics.

WTAF

It's always flappy bird

can it also make the game freeze right before your high score like the real thing

@richgel999 Impressive, but the music is a train wreck.

That's cool but it is more important to update existing games, I doubt it can do it. I tried using claude to add VS mode into Tennis NES game (it has Disassembly code) and it failed.

@iBrews Wow that’s pretty great!! Ai just makes everything new again. We’re still so early.

I wonder what @ModernVintageG thinks of the advances in vibe coding games from scratch. Personally I love that it’s opening up more options to create games 🤓

wow. I imagine it can one shot some basic games now? fascinating

This is AWESOME. I'm going to hit GameBoy games next. I have vibe-coded a twin-joystick shooter for ZX-Spectrum 128/Timex 2068 and compatibles, called ATTRIBUTE WARS

The fact that they work/look like a NES game is incredible, but wonder if LLMs could go beyond that. As in: many elements (aesthetics, gameplay, etc) were also constraints derived from human capabilities. It might be capable to extrapolate new kinds of working NES games as well.

Incredible man, been loving Fable and Opus 4.8 for iOS development. 🔥

Wow.

We’ve been doing this for NES and SNES with Codex for nearly a year now...

Source code?

Did it write the raw byte code, or compile it in some fashion? Did you give the the OP codes and an emulator to test with, or was it like 1 shotted?

cool!

where does it get the distribution to write NES games? is there a lerge cache old Nintendo game source code for the AI to learn from?

Nooo, shut up, really 😱 😱 😱 😱

That's flappy bird

don't even need fable for it to do really well on this, gpt 5.5 can make entire gameboy games with gbdk easily