Codex Builds a Playable Shooter in Minutes Where Claude Took Hours
The jump from five hours to 30 minutes for a working game prototype shows Codex is compressing the iteration cycle for solo developers.
Key Facts
- OpenAI's Codex coding environment built a playable 2D shooter in 3 minutes and 22 seconds, with a finished version completed in about 30 minutes.
- The same task took over five hours with Anthropic's Claude Code a year ago.
- Codex autonomously called GPT Image 2.0 to generate a space background when the user requested one, requiring no separate tool or manual integration.
- The Pro plan at 16,800 yen per month was required for the workload; the cheaper Plus plan hit token limits that made sustained programming impractical.
- The completed game, 'Starfall Armada,' mixes Space Invaders and Galaxian mechanics with enemy variations, a combo system, bombs, and a boss on stage five.
Reporting from 1 source: ASCII.jp.
Shinkiyo tested OpenAI's Codex coding environment by having it recreate a 2D shooter previously built with Claude Code. The first version of "Starfall Armada" ran in 3 minutes and 22 seconds, and a playable game with a space background and adjusted difficulty was finished in about 30 minutes. The same task took over five hours with Claude Code a year ago.
Codex called GPT Image 2.0 on its own to generate a space background when Shinkiyo asked for one, a step that required no separate tool or manual integration. The Pro plan at 16,800 yen per month was necessary for the workload; the cheaper Plus plan ran into token limits that made sustained programming work impractical. The completed game, "Starfall Armada," mixes Space Invaders and Galaxian mechanics with enemy variations, a combo system, bombs, and a boss on stage five. A playable version is hosted on Vercel.
Synthesized by Yomimono from the 1 cited source below, including Japanese-language reporting where cited, then editorially reviewed before publishing.