Opus 5.5

· updated

I ran a few tests with Opus 5.5 in Claude Code, with OpenRouter being callable for other cost efficient models. It’s really good compared to what was commercially available even a month ago.

This is the biggest capabilities jump I’ve seen on API accessible models in such a short time frame.

Perpetual City

This has been on-hold for a long while because I switched away from Windows, and haven’t tried to setup Unreal Engine. I gave Opus 5.5 all the C++ and blueprints for the city generation, had it describe what the C++ did in a software spec, and then asked it to recreate it in javascript absed on the spec. My expectation is that this would not work at all…. js in a browser should have much more overhead than C++. But the js version seems fast enough to actually work. It’s a little bit slower, but it’s got so much more overhead than C++. Granted, it doesn’t have all the features built into Unreal, but this is still much better than I was expecting.

Claude mostly ran into issues with empty/duplicate occupancy / area calcs, which it had trouble detecting until we made a simplified mini-map. Also z-fighting… lots of z-fighting. Fixed most of that internally, but it’s just hacky ‘have one face of wall/cieling/etc a few units furhter back than it should be.’

This version is available: here

Parallax - Monkey Island Style Game

It just did it. I told it

Create a monkey island type game, but with SG1 theming. You start as an aspiring pirate, but in the desert. After getting the stargate working, it can be used for future addon missions. Use the open router API key I set in console where needed.

This version is available: here

Interchange - AI Episodic ‘Show’

(Summary below unironically mostly written with AI)

I’d been trying to use LLMs to make a sci-fi series called INTERCHANGE. I wanted something that’s a mix of SG1, B5, and the office. I figured the Commonwealth Saga, where trains run between worlds through portals, would be a good fit since I know a little bit about the train part. The show LLMs proposed is a workplace drama set at a railway junction built around an old alien gate network. The transit network is working in the background, but the stories are about people: favors, handoffs, closures, and old obligations.

When I tried about a month ago (2026-08) none of the models worked great. The models tended to understand the setting but fill the script with technical details… multiple minutes talking about the color of an indicator. The newer models can ask whether a scene has become too procedural, whether a joke sounds like something that specific character would say, whether it’s explaining the theme instead of letting it happen, or whether the story has quietly become about the dispatch console instead of the people using it. Unfortunately it sees the issue, and then the rewrite is different but still not good dialogue. What I found improves it is to use two LLMs, tell then they are a writer from The Office, then exchange the drafts and tell each to merge and improve from the best of the other writer’s edits. That got the script to ’not horrible’ territory.

On the graphics side, Claude Opus 5.1 (I think that’s the one) wasn’t able to coordinate OpenRouter models effectively to generate consistent graphics and to proof the output. It missed simple things like characters having multiple mouths in the talking animation.

Still far from perfect, but Opus 5.5 is doing much better than 5.1.

This cost me a good bit on OpenRouter:

  • $14.95 to setup scaffolding on my computer
  • $15.75 for the first script render
  • $2.55 for rewriting the script
  • $5.33 for the second script render (less assets needed, since we had some from above)
  • TOTAL: $38.58

Current trial output available:

  • EP negative-01 - Before I improved the script writer
  • EP 00 - Forwarding Address - Slightly better script. Still talks about places the viewer wouldn’t understand the context of, and does some weird stuff like refering to ‘roads’ instead of ’tracks’. The telport animations aren’t great either.

Infographic Style Ad

I asked Opus 5.5 to look at my wife’s business website and create a <60 second ad while I went to do something else. The result looks pretty professional. Literally needed to give it no other input.

I did a similar one for STV’s Vehicles group as a test at work and it came back looking very similar. Mkaes me wonder if Anthropic built an infographic skill or something in the background. Even the folder structure looks very similar:

  • assets
    • audio
    • fonts
    • img
  • output
  • docs
  • tools
  • src
  • work
    • music
    • tts
    • img
    • cut
    • sfx
    • stills

The video it made is: here