GPT-6 Astra agent beats World's Hardest Game with one death, fully open-sourced

Developer imjustnewatai demonstrated an agent built with GPT-6 (Astra) completing all 30 levels of the classic Flash game World's Hardest Game with only one death. Full edited run is 20:51, in-game timer 10:39.075, actual time from level 1 to victory 30:06. Implementation and verification code are fully open-sourced.

Confirmed

• As clarified in m4, Astra wrote and supervised the harness: the program simulates hazards, searches routes and handles most movement, while Astra inspects screenshots and repairs the planner after deaths — tool-assisted control, not visual reflex play
• The single death occurred at level 4 (m2): after collecting a coin, the next-step search found no escape route; the fix requires verifying a survivable path of 120 ticks (3 seconds) before accepting a coin endpoint
• With the survival check added (m3), both simulated routes at the same level-4 state lasted 60 ticks; the corrected endpoint moved only 18 pixels right, with the next coin reachable within 4 ticks — an illustrative case, not a success-rate benchmark
• Verification (m5): all 30 levels passed sequential audit; 41 game assets matched initial hashes; the full edit keeps the death footage, trimming only long idle segments
• Open source (m6): GitHub repo worlds-hardest-game-recorded-agent includes harness, controller, planner, anti-cheat safeguards, methodology docs and video verification; recording starts before input, with no mic or desktop capture

Why it matters

• A reproducible, auditable demonstration of an LLM writing and supervising tools for a precision task — success comes from Astra's harness design and post-failure planner repair, not reaction speed
• Hash-verified assets, sequential audits and record-before-input anti-fake measures offer a reusable verification template for AI gameplay demos

2026-09-18 ~ 2026-09-18 · 6 related posts

• [source] GPT-6-built agent beats World's Hardest Game: all 30 levels, just one death — imjustnewatai · 2026-09-18
• Tool-assisted control, not reflex play: Astra wrote the harness and repaired the planner — imjustnewatai · 2026-09-18
• [source] The one death was Level 4: agent fixed its planner with a 3-second survival check — imjustnewatai · 2026-09-18
• One change at Level 4: survival check moved endpoint 18 pixels, next coin reachable in 4 ticks — imjustnewatai · 2026-09-18
• Run details: 10:39.075 game clock, 30:06 wall time, all 41 assets hash-verified — imjustnewatai · 2026-09-18
• [source] Full harness open-sourced: controller, planner, safeguards, and media verification on GitHub — imjustnewatai · 2026-09-18