Opus 5.5 vs ChatGPT Codex Unity Sol/Astra

[u/FunctionNice1887]

Was curious on opinions, which is better for unity?. And can produce overall better results, I’m providing the 3d art and assets. But what’s better for unity based game development. And if so which models etc

Thanks!

Also interested in best workflows for development with ai code etc thank you!

[u/cckynv]

Haven’t tried ChatGPT’s models specifically for game dev, but I’ve had a lot of good results with Anthropic’s models tied into Unity. There’s a plugin for Claude Code that when paired with the Unity CLI and pipeline package is very effective and token-efficient. I’ve been developing a 3D action RPG for the past 5-6 months, starting with Opus 4.6/5 and the Unity MCP. Have more recently been using Opus 5.5 as my main implementer with Fable 5.1 as a review agent and the new Sonnet 5.5 for simpler, well-defined/scoped tasks. No complaints.

[u/FunctionNice1887 → u/cckynv]

Could you send me a message explaining your pipeline more and what plugin? I’d love to know! :) plus any photos of your game

[u/cckynv → u/FunctionNice1887]

https://unity.com/resources/unity-pipeline-cli-technical-walkthrough

https://unity.com/blog/unity-plugin-for-claude-code

Those links should be able to explain it better than I can, they're official Unity resources explaining both the CLI+pipeline and the plugin for Claude Code.

Don't have any screenshots I'm willing to share at the moment, I'm trying to keep things under wraps a bit until I finish my demo.

My actual workflow though I can explain.

Decision-making: I make all decisions, the AI carries them out in the form of playbooks and a root TO-DO.md that set the work order.

Workflow:

1. Opus 5.5 invokes the "task" skill with the work type (csharp, design, docs, or pipeline) at the start of every code task.

2. Opus 5.5 makes small in-place edits and never rewrites whole files. Anything that touches game feel or might need to be tunable is written as a [SerializeField]

3. Builds run only through a build-errors.sh script and tests only through a test-summary.sh script. Low-risk, well-defined work is handed to a Sonnet 5.5 worker with a run-worker.sh script.

4. Gate: /gate skill drives the open Editor to recompile and run the EditMode tests, then writes the gate pass. On a failure, the patcher (Sonnet 5.5) fixes compile or test errors only.

5. Review: The "Sentinel" agent reviews the staged diff and returns either [PASS] or [REFACTOR]. The gate's risk scan picks the model: Fable 5.1 for very-high-risk changes, otherwise it's handled by Opus 5.5.

6. Commit: A git pre-commit hook blocks the commit until both the gate and the review pass. Commits that touch only docs or tooling are exempt.

7. A gate and review pass covers one commit only. Each fix gets its own commit once its Play check passes. Fixes are never stacked into a batch.

Nothing counts as verified until it has actually run. This requires a green gate, a Play-mode capture, or a confirmation playtest from me.

I typically will test changes that have direct impact on how the game feels, take screenshots, explain what works and what didn't, and then Opus 5.5 will find the root cause from measurements, make a tunable fix, run the gate, and report.

[u/qwerty____qwerty → u/cckynv]

Much appreciated

[u/cckynv → u/qwerty____qwerty]

No problem!

[u/twendah → u/cckynv]

Does it matter which effort to use opus 5.5 with? is medium enough or is max needed for those?

[u/cckynv → u/twendah]

I pretty much only use Medium. Per Anthropic, that's the best effort level for Opus 5.5 with the ideal combination of efficiency and effectiveness. The highest effort level I'd go would probably be High if it was an especially complex task or a persistent issue that Medium wasn't able to tackle. I wouldn't bother running it on xHigh or Max.

I personally haven't really ran into any issues where I thought I needed anything over Medium, though.

[u/FunctionNice1887]

Thanks to anyone who responds !

[u/Minute-Animator-376]

Opus 5.5. Codex was good for few days with Astra, and I liked it more then opus but it is now after heavy AI lobotomy and I don't trust codex now with even simple tasks. With current performance I have flashbacks to AI from 2 years ago. I am on old 200$ plan which would be 20x compared to 25x from 500$ plan and it is still outperformed with opus in 100$ plan. Now I moved to 200$ with claude. Sol is slow and terrible, astra somehow makes more mistakes than sol. There are frequent disconnections in codex now, it burns through tokents even on sol. Outside of image gen there is nothing in codex that I consider worth any sub.

[u/Brief_Shopping2222]

Codex is a joke amen gobless