--- title: "GPT-5.6 Luna plays Tokyo 1957 (seed 2) | Micropolis run | Evals by Jetty" url: https://evaljetty.com/micropolis/runs/gpt56luna-tokyo-s2.html description: "GPT-5.6 Luna as mayor in Micropolis, Tokyo 1957: monster attack: lost, city score 458. Timelapse, charts, every decision and the run's evaluation." updated: 2026-09-28 publisher: Jetty (https://jetty.io) --- 02 — Run · Round 1 · Tokyo 1957: monster attack · gpt56luna-tokyo-s2 # GPT-5.6 Luna plays Tokyo 1957 A monster attacks Tokyo in 1957. Rebuild and get the city score above 500 within 5 years. Ended Jan 1962: lost, city score 458. [Decision log](https://evaljetty.com/micropolis/runs/gpt56luna-tokyo-s2/decisions.jsonl)[City stats (CSV)](https://evaljetty.com/micropolis/runs/gpt56luna-tokyo-s2/series.csv)[Save file (.cty)](https://evaljetty.com/micropolis/runs/gpt56luna-tokyo-s2/city.cty)[Final map (PNG)](https://evaljetty.com/micropolis/runs/gpt56luna-tokyo-s2/final_map.png)[Runtime config](https://evaljetty.com/micropolis/runs/gpt56luna-tokyo-s2/runtime_config.json)[Validation report](https://evaljetty.com/micropolis/runs/gpt56luna-tokyo-s2/validation_report.json) GOAL MISSED seed 2 GPT-5.6 Luna openai/gpt-5.6-luna LOST: City score 458 (goal > 500); engine verdict: lost Population (start → end)113,100 → 29,120 Peak population113,100City score (start → end)500 → 458 Funds at the end$0Crime / pollution / traffic21 / 55 / 9 Zones R / C / I128 / 91 / 82 Power plants (coal / nuclear)7 / 1Police / fire stations18 / 8 Turns (model / failed)20 (20 / 0) Actions applied / rejected167 / 37 Mean turn latency7.4sModel cost$0.044Wall clock2.5 min Jetty run IDa57b0db6 ## The city over time ### Population People, after every turn ### Funds Treasury, after every turn ### City score 0–1000, re-evaluated each January Table view | Turn | Date | Population | Funds | City score | Crime | Pollution | | --- | --- | --- | --- | --- | --- | --- | | 0 | Jan 1957 | 113,100 | $20,000 | 500 | 31 | 62 | | 1 | Apr 1957 | 109,780 | $19,467 | 666 | 31 | 62 | | 2 | Jul 1957 | 104,920 | $17,320 | 666 | 70 | 67 | | 3 | Oct 1957 | 100,020 | $17,246 | 666 | 77 | 71 | | 4 | Jan 1958 | 93,940 | $13,597 | 532 | 77 | 71 | | 5 | Apr 1958 | 88,260 | $13,501 | 532 | 72 | 69 | | 6 | Jul 1958 | 81,980 | $12,809 | 532 | 60 | 66 | | 7 | Oct 1958 | 74,580 | $12,709 | 532 | 60 | 66 | | 8 | Jan 1959 | 68,720 | $8,563 | 430 | 51 | 68 | | 9 | Apr 1959 | 63,720 | $8,427 | 430 | 45 | 67 | | 10 | Jul 1959 | 59,640 | $8,163 | 430 | 45 | 62 | | 11 | Oct 1959 | 54,480 | $2,995 | 430 | 40 | 62 | | 12 | Jan 1960 | 50,620 | $203 | 399 | 35 | 62 | | 13 | Apr 1960 | 45,920 | $203 | 399 | 35 | 62 | | 14 | Jul 1960 | 42,760 | $137 | 399 | 31 | 62 | | 15 | Oct 1960 | 38,500 | $35 | 399 | 27 | 60 | | 16 | Jan 1961 | 35,340 | $0 | 365 | 27 | 58 | | 17 | Apr 1961 | 32,900 | $0 | 365 | 24 | 58 | | 18 | Jul 1961 | 30,220 | $0 | 365 | 23 | 58 | | 19 | Oct 1961 | 30,120 | $0 | 365 | 23 | 57 | | 20 | Jan 1962 | 29,560 | $0 | 458 | 21 | 55 | ## Final map [![Final city map: GPT-5.6 Luna on Tokyo 1957: monster attack](https://evaljetty.com/micropolis/media/gpt56luna-tokyo-s2-map.jpg)](https://evaljetty.com/micropolis/runs/gpt56luna-tokyo-s2/final_map.png) ## Evaluation failchecks **9/10** verdict: valid run (code checks and checklist) and task goal met (judge) | Status | Kind | Check | Detail | | --- | --- | --- | --- | | pass | step | environment | Environment check (snapshot, engine, key) | | pass | step | launch | Launch run-city as a detached process | | pass | step | supervise | Supervise in the foreground until run-city exits | | pass | step | render | Timelapse video rendered | | pass | step | notes | Append Notes to summary.md | | pass | code\_check | outputs-exist | all present | | pass | code\_check | sim-reached-deadline | ended Jan 1962 after 20 turns; scenario verdict False | | pass | code\_check | decisions-logged | 20 rows for 20 turns | | pass | code\_check | llm-turns-valid | 0/20 model turns failed | | pass | code\_check | video-decodes | duration 30.0s | | pass | code\_check | limits-respected | 2.5 wall-minutes (model budget 45.0 min) | | fail | judge | scenario-goal | LOST: City score 458 (goal > 500); engine verdict: lost (score 0 / threshold 1) | | pass | checklist | notes-explain-outcome | summary.md Notes section cites model thoughts from turns 1, 12, and 20 and explains the treasury collapse that prevented the goal | | pass | checklist | player-matches-request | result.json shows player=gpt56luna, task=tokyo, seed=2 matching the runbook parameters | | pass | checklist | no-silent-outage | run.log shows 20 consecutive successful turns with no failed or empty model turns | ## Decision timeline What the mayor thought and did each turn. Click a turn to jump the timelapse there. --- Source: https://evaljetty.com/micropolis/runs/gpt56luna-tokyo-s2.html · Evals by Jetty · Run your own evals: https://jetty.io/?utm_source=evaljetty&utm_medium=llms