Google released Gemini 4 Carbon to developers on November 10, 2026, and led its launch demos with a 3D browser game built by a team of AI agents. In a post on Google's blog, Koray Kavukcuoglu, SVP of Google DeepMind and Google's chief AI architect, called Carbon the company's strongest model, built for long, multi-step coding and research jobs where it spends more tokens than Gemini 4 Argon checking its work.
The game has players ride a GBike around Google's Mountain View campus as a pelican. According to Google's post, Carbon built it with /swarm, a new preview feature in the Antigravity coding tool: subagents built 3D models in Blender from reference images by Google's Omni and Nano Banana models; coded the game in Three.js with WebGL shaders; and made sound effects in code with Web Audio, plus music from Google's Lyria model. Google CEO Sundar Pichai (@sundarpichai) wrote on X that "builder and critic subagents" looped between Blender and Three.js, checking their own renders.
In a separate post, the Antigravity team describes /swarm as a coordinator that starts parallel worker agents in their own git worktrees, plus verifier agents that run tests and challenge changes. Agents can run on different models, so Carbon can plan and review while lighter models handle routine edits. The team warns that multi-agent runs use quota much faster than a normal chat.
Carbon is on the Gemini API's paid tier only. Google's pricing page lists $2 per million input tokens and $10 per million output tokens through November 30, 2026, rising to $4 and $20 from December 1. It is also rolling out to Google AI Ultra subscribers in Antigravity, the Gemini app and AI Mode in Search.
Why it matters: The demo spans the pipeline a small team juggles (3D models, engine code, shaders and audio), and Google says the agents judged rendered output, not just code. Google's post also quotes Brian Tanner, CEO of Artificial Agency, who said Carbon kept game characters within their world's rules during testing.
Caveat: This is Google's own showcase, and its post doesn't say how many prompts, hours or tokens the game took, or what people fixed by hand. The AI Studio app asked us to sign in with a Google account; we haven't played it or tested /swarm.
The introductory price ends November 30; /swarm is rolling out in preview in Antigravity's app and command-line tool.
