fp.

This is a clone of simcity 2000 I (using Opus 5.5) built over a few days. It started with a single prompt "create a typescript webgl low-poly version (full replica of game logic) of simcity 2000. the original is available here for inspection [...].zip".

It then decompiled it using Ghidra and started translating the old native PowerPC code function-by-function. After about 2 hours, using 27 subagents, i had a running version in my browser. After a follow up prompt (make sure all aspects of the game is implemented correctly and accurately), Opus decided to use a PowerPC emulator (Unicorn) and write a harness with faked Mac system calls in Python for verification, running 10,000 game days generating an identical game state. After that it has basically just been polishing, and adding a few subtle modernizations like, smog, depth-of-field and environmental sounds to make it a bit more immersive without killing the original nostalgic vibe.

All 3D and vector assets are generated with code by Opus, and the bitmap image assets are generated by GPT Image 2. The music and sounds are not genai because all AI audio models i've tried sound terrible, so the music and sounds are CC-licensed. The music is from Kevin MacLeod, https://incompetech.com/

I created this because I wanted it and to see how capable Opus 5.5 was. It turned out much better than expected, so I figured I'd share it.

Comments

qarl•49m ago

It sounds like your agents were allowed to directly read the old code and implement it as new code.

Technically this is a violation of the rules for reverse engineering. You need a gap between the agents that look at the old code and the agents that implement the new code. With an English spec connecting them.

Interestingly, that's also easy to do with agents. And apparently legal. Our entire system of software copyrights is hanging in the balance.

Crazy days.

EDIT: I heartily apologize for citing the rules for a clean-room implementation. I shall never try to explain anything to HN again.

Modified3019•29m ago

That’s a fair consideration to bring up.

qarl•23m ago

Thank you. The tsunami of downvotes seems to have stopped.

himata4113•48m ago

Opus 5.5 is probably as big of a leap as Opus 4.5 which is interesting when Opus 4 and Opus 5 were both huge disappointments.

Also this has some legal challenges, but who cares. I wonder how we're going to deal with information laundering that is enabled by AI since there's virtually no difference replicating input 2 output and rebuilding functionality from assembly.

GalaxyNova•44m ago

Seems poorly optimized

qarl•41m ago

Given the way he implemented it - I suspect it is optimized exactly like the original.

slopinthebag•39m ago

yep this stuff is super interesting. we're seeing rust rewrites of games like modern warfare 2 [1][2], and mashups with cod, minecraft, and skate 3 [3][4][5]. there is a large active discord community of gamers and modders sharing tips and guides on how to do this. none of them are really programmers, they're just sharing prompts and codex/claude code does the rest. i don't think llm's are capable of designing new games but they're wizards at reverse-engineering and mashing up existing games, which kind of makes sense for a computer.

[1] https://github.com/vladtrc/iw4L

[2] https://www.youtube.com/watch?v=9UbADrcEW5w

[3] https://github.com/chasmlol/2010-rust-rewrite-mashup

[4] https://www.reddit.com/r/bevy/comments/1wuu7bx/are_you_seein...

[5] https://www.reddit.com/r/bevy/comments/1wuag9d/skate_3_was_r...

qarl•31m ago

> i don't think llm's are capable of designing new games

I invite you to examine my clean-room implementation of Animal Crossing, coming out next week. Infinite expanse and multiplayer.

I'm not sure what you mean by "new games" - but substantial changes to existing games are extremely easy.

Also - the animals will be LLMs - so when you talk shit about them they'll remember and get revenge.

slopinthebag•30m ago

no i just mean i don't think they're creative enough that you can say "computah, make me an indie hit". you can absolutely use it to implement your own novel designs tho.

thih9•28m ago

My phone got uncomfortably hot after a few minutes.

DonHopkins•26m ago

That means your nuclear power plant melted down.

dofm•24m ago

It was feeling shame.

egeozcan•21m ago

Opus 5.5 made me a launcher for Red Alert 2 that skips all the menus and directly lands in the game with perfect resolution and very good performance. It even fixed a lot of bugs with the game and added some custom units and a lot of balancing. I didn't publish it anywhere because of copyright worries, and everyone can do this with a couple of prompts anyway.

BTW, for the balancing tests, it decoupled rendering from game logic and can run 32 parallel games under my good old 3950X.

https://imgur.com/a/uEretZ0

What I'm trying to say is, after seeing that, I think this doesn't surprise me at all. Just a couple of week ago this would have blown my mind.

henriquecm8•13m ago

I wonder if it would be possible to fix Deadly Premonition's buggy pc port. I've played a few hours, then it started to always crash after opening it, I tested everything I could think of and never got it running again.

egeozcan•8m ago

I have zero doubt, it definitely can. Just throw claude and the game in a VM with a bunch of tools and let it go wild.

drudolph914•7m ago

from a programmer/technical perspective, very cool and technically impressive. gonna have to try this myself with opus 5.5

from a consumer perspective, I don't think I fully know why yet, but I just don't have a desire to play any of these AI generated games. I'm curious what other people here think (even if we're all little bias here due to their technical curiosity - very curious what you think)? like, I generally feel that because the technical execution for something like is diminishing to zero, the half of me that likes to play and look out for new games doesn't really see why this is special or interesting? I too have ideas and can put a couple hundred dollars into opus 5.5 and get it to make an entire game. once this all becomes normalized and everything from games, to books, to movies, tv shows, etc become something that can just be generated at a good enough quality that I wouldn't know the difference between a person and machine, I guess what is the point of any of this? I feel like knowing that a machine made instantly reminds me that literally nothing about this matters. a lot of the joy behind getting into something like a game or book was to be able to be apart of a community and talk to like minded people.

and I want to be clear, none of this is criticism towards the demo here - the demo is cool. I'm just also curious what people think the 2nd/3rd/4th order effects will be when making anything becomes so normal, that it's just another part of your day-to-day? I guess, I'm kind of searching for an answer to the question of why should I really care about this if it's all a zero sum game and a race to the bottom?