OpenAI’s flagship model GPT-6 Astra completed Valve’s 3D puzzle game Portal from start to finish without human intervention, reaching the credits after 23 hours and 43 minutes. The trial, conducted by AI and large language model enthusiast CozyBlaze, involved 3,336 tool calls and incurred $571.18 in API costs, covered by a $200-per-month Codex Pro subscription. Astra operated through a Model Context Protocol server and a modified SourcePauseTool plugin that paused the game while the model analyzed screenshots and player-position data. It repeatedly retried failed sections and eventually defeated GLaDOS through trial and error. CozyBlaze published the setup on GitHub, but said the result should not be treated as an AI benchmark because substantial problems remain. The experiment demonstrates autonomous interaction with a 3D environment, although the cost of completing a single game highlights the challenge of making such agents economical.