GoKawiilAI Can't Recreate Thrust (But It Can Help You Understand It)
A turn-based 4X strategy game I built from scratch — custom WebGPU engine, eight civilisations, no install. Play it in your browser right now.
I asked Claude to recreate the classic 1986 game Thrust for me in the browser. It created slop but then things spiralled out of control.
Thrust was one of my favourite games on the BBC Micro — written by Jeremy C. Smith and published in 1986, it’s a deceptively deep game with amazing physics and gameplay. You pilot a ship through caverns, collecting fuel, avoiding turret fire, and retrieving a pod for bonus points while fighting gravity and momentum. Jeremy went on to create the even more impressive Exile with Peter Irvin before tragically dying in an accident in 1992. He was somewhere between 16 and 18 when he wrote Thrust. You can play the original online.
I’ve got a BBC Master on the desk beside me and I still occasionally fire up Thrust on there along with some of the other classics. It’s one of those games I keep returning to along with Elite, Exile and Holed Out. I’ve now recreated three of these in different ways… the fourth is looking increasingly unavoidable.
Starting with slop
Anyway. I guess I’d been thinking about Thrust as one morning recently I somewhat casually asked Claude Code to create it for me in the browser. I think I’d been reading the latest proclamations of capability from OpenAI and Anthropic and so I put together quite a comprehensive spec, gave it access to the original disassembled source code, screenshots, and said “go and recreate Thrust for me.”.
It created something for which the term slop would be too kind, it very vaguely resembled Thrust — it had the scanline stuff, sort of — but it was truly dreadful. It hadn’t even got gravity working right, the ship didn’t fall properly, the controls felt weird, and it was just… grim. In some ways its amazing that it created something that sort of worked and sort of looked like Thrust but it was not playable and nothing close to the elegance and beautfy of the real thing.
And that’s the thing about a game like Thrust. You could knock out something superficially similar pretty quickly — just run at the device frame rate, use standard delta-time physics, draw some caverns. But it would feel nothing like Thrust. The magic is in the specific timings, the weight of the ship, the way momentum builds. Particularly if you’ve played the original then those details are everything, and an AI working from a text description, and it turns out even the original source, can’t capture them.
The archaeology
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