Giving Your Agent Eyes with Game Boy Hacking

2026-07-03 · page · source ↗ · source summary

Ian Langworth wires a Game Boy emulator (Gearboy), a Ghidra disassembly toolkit (GhidraBoy), and an MCP server (GhidrAssistMCP) together so Claude can disassemble, inspect memory, set breakpoints, and hunt for secret content in old ROMs. The real finding isn't about Game Boy reverse engineering — it's that giving an agent a feedback loop where it can observe its own progress is what unlocks surprising behavior. The specific tools are incidental; the pattern generalizes.


Key Quotes

"are there scenes, endings, or content locked away in the ROM that I was never able to reach?"

This is "exactly the shape of goal you can hand to an agent and let it grind on." Open-ended exploration with a measurable target — the sweet spot where agents outperform directed prompting.

"the thing that matters is the feedback loop"

Not the emulator. Not the MCP server. Not the model. The loop. Give an agent a way to see whether it's approaching its goal, then let it spin. This is the same insight behind Webwright (Playwright as feedback loop), Browser Use (browser as observation surface), and the entire Computer Use is 45x More Expensive Than Structured APIs calculus — vision is expensive but sometimes it's the only feedback mechanism that works.

Claude would set a breakpoint, instruct Ian to play a specific stretch of the game, then ask him to modify a byte and report what changed.

The human-agent collaboration pattern here is notable: the human plays the game (operates the environment), the agent reasons about memory and sets breakpoints (does the analysis). This is neither fully autonomous nor fully manual — it's a tight collaborative loop where each side does what it's best at. Same pattern as the DeepSeek Reverse Engineers TeamSpeak Licensing workflow with Ghidra + x64dbg, but here the emulator's visual output closes the loop.


Key Themes

#feedback-loop #reverse-engineering #agent-design #mcp #emulator #collaboration #computer-use


The Setup

Three pieces wired together:

The Game Boy's Sharp LR35902 assembly is simple compared to modern ARM or x86 — small instruction set, well-understood memory map — making it an ideal target for LLM-driven reverse engineering. Claude demonstrated solid ability to understand subroutines by inspecting memory, taking screenshots, and comparing them over time.

Together they mapped out health values, enemy rosters, and the memory flags checked to determine which screen should display.


Critical Analysis

The Game Boy is a surprisingly good choice and Langworth knows why. The LR35902 ISA is simple enough that an LLM can reason about it from first principles, but the games are complex enough to be interesting. This isn't a toy demo — it's a smart selection of the right target for the current capability envelope. The same principle applies to choosing which problems to point agents at: pick targets simple enough they can reason about, complex enough the result matters.

The feedback loop insight is correct but underdeveloped. "Give an agent a way to see whether it's achieving its goal" is the one-sentence summary of a dozen techniques: computer use agents, browser automation, test-driven development loops, and now emulator-driven reverse engineering. But not all feedback loops are equal. The article doesn't explore what makes a good feedback mechanism — latency, signal clarity, actionability, cost — versus a bad one. The Computer Use is 45x More Expensive Than Structured APIs analysis is the missing companion piece: vision is 45x more expensive than structured APIs, so you'd better be sure the feedback is worth the cost.

The human-agent collaboration model is the sleeper insight. Langworth didn't try to fully automate the loop — he played the game while Claude inspected memory. This is a smarter division of labor than either full autonomy or full manual work. The human handles real-time motor interaction (which agents are terrible at), the agent handles memory analysis and hypothesis generation (which humans are slow at). This pattern — human as operator, agent as analyst — is under-explored compared to the "fully autonomous agent" narrative.

The 3-minute format is both a strength and a weakness. The article is crisp and memorable precisely because it doesn't over-explain. But "how do I apply this to my own domain?" is left entirely as an exercise for the reader. The bridge from "Game Boy emulator" to "my production system" is not obvious, and the article doesn't build it. The reader who needs it most — someone who hasn't yet internalized the feedback loop concept — gets the inspiration but not the instruction.

The sibling article is DeepSeek Reverse Engineers TeamSpeak Licensing. Same toolchain (Ghidra + MCP), same collaborative loop, different model and target. Read together, they make the case that the harness matters more than the model: Claude refused TeamSpeak RE on safety grounds but happily disassembled Game Boy ROMs. The task shape is identical; the alignment filter is the variable.

Kuna — Agent-First Decompiler takes the feedback-loop insight one level up. Langworth's LLM drives a decompiler to analyze ROMs; Basque's LLM writes the decompiler itself, using benchmark-driven refinement — the same feedback-loop pattern applied to tool construction rather than tool use. The loop is the primitive; whether it's aimed at a binary or at the tool's own output is just a matter of what you measure.

Everything I Own, Owned points the same loop at hardware you actually own. Schlarp ran the identical pattern — agent + a target with a data connection and an update mechanism — against five live peripherals (webcam, monitor, mic, capture card, key light) and came away with working shells and patched firmware in ~13 hours of churn. The notable difference: Langworth's target was a sandboxed emulator, so the stakes were curiosity; schlarp's targets were the devices on his desk, so the conclusion is a threat model — if this is cheap now, assume any attached device may already be implanted. Same loop, one pointed at a ROM, one pointed at your microphone.


Source: ai.statico.io, Ian Langworth, 2026-07-02 Last updated: 2026-07-03