Pac-Man from one prompt, 36 ways
PacBench, a gallery of 36 playable Pac-Man games, each made by a different model and harness from the same one-line prompt and scored on controls, ghosts, maze, and sound, with time, tokens, and cost per run. Opus 5.5 in Claude Code tops it at 99.
“Models and harnesses recreate Pac-Man from one short prompt.”
Create a Pac-Man game in a single html page
Make it yours. Swap "Pac-Man" for another arcade game, or start from the longer bench/prompts/pacman.md, which spells out the maze, four ghost behaviors, and the rules that keep a run fair (one file, no web, work alone).
How it was made
Each model and harness gets one shot, with no follow-up prompts or fixes. The scores, out of 100 for controls, ghosts, getting stuck, maze, and sound, come from Opus 5.5's re-test of the live games on 2026-09-28: a 90-second automated play test plus a source and maze audit. The early runs, including the top-scoring Opus 5.5 game, used this one-line prompt. Newer runs added through the repo's runner since 2026-09-30 use the longer bench/prompts/pacman.md (linked below), and their cards say so. The recording here is the Opus 5.5 game being played.
$1.99 for the Opus 5.5 run in Claude Code; every card lists its own time, tokens, and cost.
Claude Code · Codex · Cursor · Antigravity · Grok Build · Claude Opus 5.5 · Claude Fable 5.1 · Claude Sonnet 5.5 · Grok 4.7 · GPT-6.1 Sol · GPT-6 Astra · Gemini 3.8 Flash · Kimi K3 · Plain JavaScript
9.3 minutes for the Opus 5.5 run in Claude Code; every card lists its own
Source and credit
GitHub · Sep 28, 2026 · 80 points · 50 comments
Authorship not stated by the source
Published instructions: The PacBench site, quoted as the test prompt (the Show HN post quotes it with "HTML" in capitals)
Look notesby Reference
Reference's recording of the top-scoring game, Opus 5.5's: an arcade-style Pac-Man with a ghost roll-call attract screen, a READY! start, and a run around the blue maze that ends with Pinky catching Pac-Man.
- Color
- Black background, royal-blue double-line maze walls, peach pellets and power pellets, a yellow Pac-Man, and red, pink, cyan, and orange ghosts.
- Type
- Blocky white arcade type for 1UP and HIGH SCORE, a yellow PAC-MAN title and ghost names in their own colors on the attract screen (-SHADOW "BLINKY", -SPEEDY "PINKY"), cyan PLAYER ONE and yellow READY! in the maze, and a grey key hint line (ARROWS/WASD MOVE, P PAUSE, M MUTE).
- Framing
- A near-square 10:11 frame filled by the maze, with the score along the top, spare lives in the bottom left, and a cherry in the bottom right.
- Structure
- The attract screen with the four ghosts and point values, PLAYER ONE and READY!, Pac-Man eating along the lower corridors as Blinky and Pinky leave the ghost house, the score climbing to 240, Pinky catching Pac-Man by the left tunnel, the maze emptied during the death, and a fresh start with one fewer life.
