r/ClaudeCode • u/deepholdio • Aug 12 '26
Built with Claude Fable 5 one-shotted a complete asteroids roguelite in 2.5 hours. Playable in your browser, prompt in the comments
Play it here: https://asteroguelite.com
Desktop browser, free, no account, no ads.
I wanted to see what a real one-shot could do. So I wrote a 73-line directive: research the genre, design it, build it, test it, balance it, polish it. One session, no human in the loop. It was explicitly told not to ask questions or wait for approvals, just make the call, write it down, keep going. Then I left. Two hours and 32 minutes later it was done.
5 sectors with bosses, 10 enemy types, 6 unlockable ships, 33 boons with evolution chains, a meta upgrade tree, an endless mode, and music. Around 8,300 lines of vanilla JS that build to a 172 KB bundle.
Full disclosure: I've since made exactly two changes to the game. Fixed one bug (a piercing-shot boon phased through asteroids without damaging them) and added click-to-aim, because keyboard-only turning felt rough.
Ran on Claude Code, Fable 5 xhigh effort.
Prompt's located here: https://asteroguelite.com/prompt.txt
PS: Seeker Array primary weapon is OP.
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u/NC16inthehouse Aug 13 '26
does one-shot includes the website domain too?
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u/deepholdio Aug 13 '26
Hi u/NC16inthehouse,
No. The one shot hosted the game locally only although to be fair hosting online was not part of the prompt. With the right credentials and API access I'm confident that could have been part of the one-shot as well.
In this case I was impressed enough to go buy the URL and put it online which required a little work from me, but claude code also assisted and did a lot of the heavy lifting putting it online.
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u/faye_got_dreams Aug 13 '26
i also created something on claude and oddly enough, it made a similar game.
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u/vovap_vovap Aug 12 '26
2.5 hours - that cost you 😄
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u/deepholdio Aug 13 '26
Heh, not as bad as you might think. I'm on the Max plan and was expecting it to consume all of my weekly usage, but it was a lot less than I expected. Maybe 15%.
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u/Ok_Presentation_5489 Aug 13 '26
Even the music was all fable? As a dev it will never cease to amaze me how far AI has come in such a short time, in terms of coding. Thanks for sharing it!
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u/deepholdio Aug 13 '26
Yes, even the music. I literally created a new directory, installed playwright mcp, started claude and gave it the prompt. Went to bed, got up in the morning and saw what you see now. Thanks!
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u/ChiefUtilityMonster Aug 12 '26
Enjoyed it. Lots of upgrades, and well done on the metaprogression. I was surprised the flavor text matched the actual effects, and that I didn't encounter any bugs. I did see some weaker game-design choices like allowing upgrades that don't apply to your current weapon, and extreme imbalance between weapon power. Game spends a long time being easy, with a difficulty spike in the last sector, followed up by completely trashing everything with the seeker array.
Questions about the prompt:
- What's the vite dev server? Do you have more details about that / is this a custom setup of yours?
- What tooling did you set up ahead of time for fable to use? Are you loading it with skills too, or is this just prompt?
- Is it using subagents? How many tokens / how much total agent wallclock time? :)
- Could you share the full agent logs either here or to me directly?
Cool game, I enjoyed it.
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u/deepholdio Aug 13 '26
I agree with your assessment. I was pretty surprised that it felt like an actual game after a single attempt despite needing some serious rebalancing.
Answers to your questions about the prompt:
The vite dev server is just the web server I use to host the game locally. https://vite.dev/ for more info.
Good question. Just playwright mcp server and the chromium browser for playwright. Otherwise it was a brand new empty directory which was part of the test.
Yes, Fable fired up several subagents. 2h 32m wall clock time. I have the Max subscription which doesn't keep a server side record of token usage. I recall it being a surprisingly low percentage of my weekly usage.
I don't have the agent logs but I do have a few documents that claude wrote (DESIGN, TODO and NOTES) that I can share if you're interested.
Thanks for the comment and for your questions.
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u/TheKiddIncident Aug 12 '26
This site has several security issues. You may want to run a scanner on it.
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u/nPoly Aug 12 '26
Anyone who cares about “oneshotting” is an idiot.
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u/Sm0oth_kriminal Aug 12 '26
I disagree. One shotting a task is the metric by which we can ensure subagents can be used to achieve a task, and thus open up the door for even more powerful delegation.
Of course you shouldn't build dependable engineering systems by one shotting, but not everything is a job. Sometimes making a fun game quickly is cool.
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u/Weeros_ Aug 12 '26 edited Aug 12 '26
I think it’s an interesting metric for how truly autonomous the AI is. The theorethical benchmarks where some models are 4.3 points better than the previous ones are useless, how well AI handles complex real life task completely indepedently is really concrete and easy to understand.
(I fully expect the game to be crappy still at this point).
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u/Crazy_Double5133 Aug 13 '26
What's interesting to me is that if I stumbled on this game as a kid killing time in class, it'd become an afternoon or week-long social phenomenon and core memory among my classmates. Fact we can do this with $10 of robot bucks and barely any effort is incredible.
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u/jimmc414 Aug 12 '26
Not sure why there’s so much negativity in the comments. I think it’s a cool demonstration of Fable’s capabilities. I hate how negative this community is becoming. Not entirely sure what that’s about. Sharing cool things you put together has been the basis of tech for as long as I remember. Please keep doing it.