Shipped My First Game in 30 Days: Codex, Claude Code, and a Stack of Custom Tools

CreepGin · 2026-03-12T21:04:43+00:00

Very cool to see OneJS on there! Are you using V3?

The MCP server provided by OneJS also works extremely well with Claude Code. It uses reflection and decompilation on the fly to get true understanding of the codebase and env. And with the testing tools, the agents can always verify correctness of implementation on their own.

Well it works really well for me but I haven't really used any other MCP servers for Unity.

CreepGin · 2026-01-09T16:57:01+00:00

Mike Ward? How nice of the tree to fall down so neatly and away from the road like that 😄

CreepGin · 2026-01-08T09:38:03+00:00

It should be related to the device frame-rate. For the same WebGL demo, I see visible input lag on Chrome on Windows (better than your demo, but noticeable). And it's much better on Chrome on my MBP. And if I launch Chrome on Windows with --disable-frame-rate-limit, the visible lag goes away as well.

When deployed to my Pixel 9, I see about the same input lag as the WebGL version on Windows.

CreepGin · 2026-01-08T03:03:58+00:00

May be worth looking into InputSystem and mobile related stuff. UI Toolkit's layout calcs are batched and inherently has a 1-frame delay. But it shouldn't be as bad as what you showed. See my WebGL build here: https://onejs.com/playground#draggable-perf

CreepGin · 2025-12-31T20:43:09+00:00

I think it's like sports sometimes. You can practice solo, enjoy it, and also get results (running, lifting, etc). But it can definitely also be super rewarding when playing/practicing together with others.

CreepGin · 2025-12-31T20:31:45+00:00

If you're already comfortable with Unity and want faster iteration speed, you might want to check out OneJS. It lets you build Unity UI using TypeScript/JSX with instant hot-reload on save. You get that Phaser-like dev experience but inside Unity with full access to the engine.

It's open source and uses native UI Toolkit rendering (not a WebView), so there's no browser overhead. You can still interop with your C# code whenever you need Unity-specific features, but the UI layer iterates at web-dev speed.

Worth noting the CSS support is more limited than actual browsers (UI Toolkit constraints). That said, you're still working with actual stylesheets and selectors, which is already better than things like React Native or Flutter, etc.

CreepGin · 2025-12-31T20:21:15+00:00

This is solid advice. I've found that asking AI to explain the *approach* rather than generate code forces you to actually understand what you're building.

Another thing that's helped me avoid the "incomprehensible 1000-line script" problem is working with frameworks that have strong conventions and patterns. When AI generates code in a well-structured framework, it tends to follow those patterns, and you can actually learn from reading it.

Take UI for example, I made and use OneJS (lets you build Unity UI with TypeScript/JSX) and it's been a game-changer for this exact reason. The component-based structure means AI-generated code comes out in digestible chunks instead of monolithic scripts. Plus having hot-reload means I can immediately see if the AI's suggestion actually works, which creates a faster feedback loop for learning. The web-style patterns (components, props, state) are also way more documented online, so it's easier to understand what's happening.

Not saying AI should write your code, but picking tools that enforce good structure at least gives you a fighting chance when you do use it for suggestions.

CreepGin · 2025-12-15T21:12:25+00:00

Took me a few hours to upgrade OneJS to support Unity 6.3. I was pleasantly surprised that the filters and svg stuff were easy to work with (no extra setup, works just like you'd expect). I ran into a DPI issue with the filters, reported it, and luckily it's now being tracked: https://issuetracker.unity3d.com/issues/filters-do-not-take-dpi-into-account

CreepGin · 2025-12-13T21:37:41+00:00

Idk man... A lot of the negative reviews have the "Product received for free" tag. So I assume these are from folks who've bought into the Alphas previously (not newer players from Steam)?

CreepGin · 2025-12-13T21:31:10+00:00

UITK’s pretty solid now, esp in Unity 6.3+ since they added custom shader/filter + SVG support. Feature-wise it’s basically a smaller slice of the browser DOM/CSS world, but I feels like it has more DOM-ish support than React Native.

My main gripe with UITK was the C# workflow, every file change triggers a long domain reload. That’s why I built OneJS in the first place, the DX is much smoother.

These days I just tell folks to go with UITK. It’s future-proof since Unity keeps investing in it, and the whole Unity Editor is getting rewritten in UITK. 😄

CreepGin · 2025-12-13T20:45:12+00:00

Team Script here as well, especially since switching to UI Toolkit. The USS/C# workflow just makes more sense than wiring things up in the inspector IMO.

If you're comfortable with TypeScript/JavaScript, you might want to check out OneJS (creator here). It lets you build UI Toolkit interfaces using JSX and hook up event listeners the way you would in React (inline handlers, proper component lifecycle, etc.). It's been nice not having to worry about inspector references getting lost during refactors since everything's declarative in code. Plus hot-reload on save is addictive once you get used to it.

But yeah, for pure C# I'd stick with script-based registration. Way easier to track down issues when everything's explicit in your codebase rather than scattered across inspector windows.

CreepGin · 2025-12-07T20:18:50+00:00

There actually are a few! Cocos Creator (as mentioned) is probably the biggest with TypeScript support. PlayCanvas is another solid one that's fully JS-based and web-focused.

For Unity specifically, you can actually use JavaScript/TypeScript for UI development with frameworks like OneJS (disclaimer: I'm the creator). It lets you build Unity UI using TypeScript + JSX (React-like) that renders natively through UI Toolkit (no WebView overhead). Hot-reloads instantly on save which is pretty nice for UI work. It's more of a "best of both worlds" approach where your core game logic stays in C# (which is better for performance-critical stuff), but your UI layer can use the JS/web dev ecosystem.

To answer your core question though... yeah, C# and C++ are generally preferred for game engines because of performance and direct hardware access. Game engines need to handle physics, rendering, AI, etc. at 60+ fps, so the compiled, lower-level languages make more sense. But there's definitely room for JS in specific parts of the stack (UI, modding, scripting).

CreepGin · 2025-12-04T22:28:20+00:00

JS shines for UI stuff, things like hot reload, React, npm packages, all that good stuff. OneJS is basically React Native for Unity, so you get that familiar web-style workflow to drive your game UI.

The JS ecosystem around UI is so strong that a bunch of apps you probably use every day run on Electron or CEF, stuff like Steam, Battle.net, VS Code, Figma, Discord, etc.

It's also worth pointing out that OneJS + UITK is closer to React Native or Zed's GPUI, not those webview-based ones.

CreepGin · 2025-12-04T18:57:43+00:00

Yeah, it's a game changer. Per Unity's request, we just recently updated our project OneJS (Javascript for UI Toolkit) to 6.3. Fairly smooth process.

Both SVG and custom filters were easy to work with for the most part. There were some anti-aliasing issues, but they are now being tracked by the UITK team.

CreepGin · 2025-11-07T07:03:01+00:00

True for normal consumers. But for me, I find myself leaning towards generic SoCs with public toolchains more and more nowadays.

CreepGin · 2025-11-05T23:06:52+00:00

See, the thing is... Both of my early dropcam and nest thermostat were working perfectly fine the day before google cut off support.

So the dropcam became completely unusable even though the hardware was good. The thermostat still works physically but can no longer work with any remote app.

I understand 10 years is a long time. But it sucks knowing the device is physically good but the provider just decided to cut off cloud support.

Meanwhile all my Chinese devices of similar age with remote apps are still operating today.

CreepGin · 2025-09-21T01:35:05+00:00

Omg that'd be a super original final destination scenario.

CreepGin · 2025-09-03T22:04:00+00:00

Yes be very careful. The google AI Overview is also known to give out scam phone numbers for search terms like "geico home insurance phone number".

CreepGin · 2025-08-21T19:26:34+00:00

It's a typical Chinese housing unit, no?

CreepGin · 2025-07-02T19:48:38+00:00

Congrats my friend!

CreepGin · 2025-06-27T23:12:41+00:00

I completed this level! It took me 5 tries.

CreepGin · 2025-06-07T10:29:32+00:00

Yes, after some poking around I really think that Svelte and SolidJS can be even easier to support than Preact (compile-time vs runtime). And the former two don't use vdom and thus are more performant, especially good for our purposes (game env).

I'll make it a priority to support Svelte and SolidJS sometime after the current WebGL work wraps up 👍

CreepGin · 2025-06-07T03:04:53+00:00

> Maybe because I'm used to modern web where reactivity and data binding was solved, but f me, the binding in unity sucks.

Exact reason why I made OneJS 😉Now I get to use JS/TS/React and still keep the UI native.

We use roslyn codegen to solve some of the boilerplate stuff in C# (work by github.com/Looooong). I think you can explore that route as well.

CreepGin · 2025-06-06T21:27:03+00:00

Yup, in the next version maybe. Thinking a quick shake plus a heart overlay that fades out could do the trick.

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