One prompt, 8,429 wrong pixels to 2: how Claude Opus 5.5 finally made Prince of Persia look right
Analyzing Frontier Model Progress with My Favourite Game: Prince of Persia
I handed the original Apple II Prince of Persia source to each new frontier model and asked it to port the game to C#. Opus 4.6 picked the wrong architecture; Codex polished the surface; Opus 5, given tools to watch the real game, rebuilt the engine and produced a playable version. Opus 5.5, from a single prompt, ported SDLPoP's room-drawing routine and cut the first screen's pixel differences from 8,429 to 2.
The biggest jump wasn't only the models getting smarter. It came from giving them a way to see the original and test themselves against it.
- criemen
A German magazine (c't) ran a Asteroids programming contest in 2008 - create a client with access to the emulator output of the game that provides keyboard inputs to control the game.
The highest scoring submission that won the contest had a high score of around 137k.
Last week, I had GPT-6 Astra, Sol and Luna implement and hill-climb on this task, as I wanted to see how big the difference in smartness is. Luna implemented something, but never exceeded ca. 20k points, with a large variance.
Sol got something in the area of the humans implementation.
Astra, which finished fastest, had a highscore of around 1.7Mm when the game seemed to fairly reliably crash. On the way, it disassembled parts of the ROM to extract information about the game.
I didn't do a ton work to document and measure the specifics, but it was very impressive.
- Kuyawa
I am going to try to build the original Prince of Persia using Swift as it is the best language for building a macOS game. Being a classic 2D cinematic platformer, Apple's native frameworks provide exactly what I need without the overhead of a massive cross-platform engine, and I love simplicity
So here goes my weekend, flag this and get a life
- tehlike
Instead of fixing a broken version, maybe each model should have started from scratch
- rhipitr
Off tangent but the latest prince of Persia game is really fun
- smokel
The prompts provided are atrocious. It's amazing that the LLMs actually built something useful.
> My first prompt was simple: "in this original code there 6502 assembly code for prince of persia, use the save level files and try to do it in c# console."
Do what in the what now in the console?