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YOU CAN MAKE THE LEGO GAME BOY ACTUALLY PLAY GAMES

A custom circuit board, a real screen, and BrickLink instructions turn the LEGO set into a working handheld.

by Theremin Hero (Greig Stewart)

FULL CAD BOM FIRMWARE DOCS

Open-hardwareDisplays

Built withESP323D printing

difficulty
●●●●○
time
a weekend-plus
license
All rights reserved (no licence file)
repo
repo ACTIVE14 stars

WHAT YOU’LL NEED

Videos
1
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COMPAREE VERDICT

This is a display piece first and a playable handheld second: you buy the official LEGO set, add custom boards and rebuild the set around them. The KiCad files, Gerbers, pick-and-place file, BOMs, STL parts, BrickLink Studio models and a PDF for the top-part assembly are in the repo, but there is no licence file, so treat this as a reference design you can build for yourself, not something you can fork or sell. The board is an ESP32-S3 design with a 2.4-inch screen, speaker, microSD and a 300 mAh battery charged over USB-C. The single hardest part is not the board - it is the rebuild: some LEGO parts come out or get swapped, and you follow the LEGO instructions and the OpenBrickGB material at the same time. The most likely thing to go wrong is the buttons: they need mechanical travel through the button boards, membranes and spacers inside the LEGO parts. If you want a working Game Boy and do not care about the LEGO shell, buy a different handheld. If you want the LEGO set to actually boot, this is the most complete public design for it, and the creator offers kits that need no soldering.

GOOD TO KNOW

  • —KiCad PCB files, Gerbers, pick-and-place file, BOM CSVs, STL parts, BrickLink Studio models and a PDF for assembling the top part are in the repository.
  • —Firmware is a Retro-Go fork at greigs/retro-go, releases page has binaries.
  • —There is NO licence file — the files are public but all rights reserved, so this is not open source and you cannot sell derivatives.
  • —The LEGO set itself (72046) is not included; you buy that separately and rebuild it around the boards.
  • —The creator also sells kits, so ordering the PCB and parts yourself is optional.
  • —No commercial use allowed without permission.

Parts to buy

8 items

From our check of the build. Exact quantities and part numbers are in the creator’s BOM.

  • LEGO Game Boy set 72046Find
  • Main PCB and three button boardsfrom the repo files
  • ER-TFT024-3 2.4-inch screenFind
  • 702025 300 mAh LiPo with PH connectorFind
  • SpeakerFind
  • Silicone membranesFind
  • Tact switchesFind
  • FAT32 microSD cardFind

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Can I build this?

PrintSmall internal spacers and holders for the button boards, screen and USB-C socket (STLs in the repo)
BuyLEGO Game Boy set 72046, main PCB and three button boards (order from the Gerbers or get the kit), ER-TFT024-3 2.4-inch screen, 702025 300 mAh LiPo with PH connector, speaker, silicone membranes, tact switches, a FAT32 microSD card
Toolssoldering iron, flush cutters for LEGO parts, screwdriver, 3D printer (PLA and TPU), tweezers, multimeter recommended
SkillsFine-pitch SMD work if you assemble the main board yourself (0603 passives, leadless QFN/WSON chips, ESP32-S3 module) — or use the JLCPCB part numbers and pick-and-place file for factory assembly. Plus LEGO part modification, firmware flashing via USB, and patience for a two-stage build.
TimeA weekend-plus: PCB assembly 3-4 hours, printing and fitting parts 2-3 hours, rebuilding the LEGO set around the board 4-6 hours, firmware and testing another 2 hours
CostHigh: the official LEGO set plus either the creator's kit or your own boards, screen, battery and parts; neither the repo nor the writeup lists prices.
SafetyThe 300 mAh LiPo is charged by the board's BQ24040 charger over USB-C - check connector polarity before plugging it in, and do not pinch or puncture it when closing the LEGO shell. No mains voltage.

Build at your own risk. Projects involve tools, electronics and sometimes mains voltage — follow the creator’s safety notes.

Videos

The creator's own videos: Part 1 shows the working handheld (running DOOM), Part 2 covers the kits. They are demos rather than step-by-step build guides; assembly is in the PDF and BrickLink files.

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Gallery

Start here

Navigation into the creator’s own docs — we don’t rewrite the guide, we route you to the source.

  1. 1.Buy the LEGO set first and build it once to understand the structure(You need to see how the official build works before you modify it.)
  2. 2.Read the OpenBrickGB PDF assembly guide and the BOM (The BOM specifies exact part numbers for the screen and passives; substitutions will not fit.)
  3. 3.Order the PCB (Gerbers are in the repo) or buy a kit from the creator (Kit link is in the Hackaday.io writeup if you want to skip part sourcing.)
  4. 4.Print the small internal parts: the A+B board holder, the Start/Select spacers and the emulator-menu button (STLs are in the 3D Printed Parts folder; the kit includes these parts if you would rather not print them)
  5. 5.Assemble and test the PCB before installing it in the LEGO shell (Flash the firmware and confirm the screen and buttons work on the bench first.)

KNOWN ISSUES

  • The repository has no licence file — the design is public but not open source, so you cannot sell builds or derivatives without asking the creator first.
  • The LEGO set is not included; if you do not already own it, factor it into the budget before ordering parts.
  • The screen model in the BOM is specific — a different IPS panel will not fit the LEGO window opening or the 3D-printed mount.
  • The buttons need mechanical travel inside the LEGO parts: they work through small button PCBs, silicone membranes for A and B, and printed spacers, so print the spacers accurately and test each button before closing the shell.
  • You are rebuilding the entire LEGO set around the board, not just dropping the board in — expect to follow two instruction sets at once and modify a few LEGO parts with flush cutters.
  • The Retro-Go firmware fork is at greigs/retro-go, not the upstream Retro-Go repo — make sure you flash the right binary or the controls will not map.

Can I sell these if I build extras?

No. The repository has no licence file, so all rights are reserved. The creator sells kits, so contact them if you want to do anything commercial.

Do I need the LEGO set or can I print the shell?

You need the real LEGO set. The printed parts are internal brackets and button stems, not the outer shell — the whole point is that it looks like the official set.

What games does it play?

Game Boy and Game Boy Color games, through a Retro-Go fork on the ESP32-S3, and the creator shows it running DOOM too. You load ROMs you own from a FAT32 microSD card; if there is only one ROM on the card, it boots straight into it.

How long does the battery last?

The BOM specifies a small 702025 300 mAh LiPo with a PH connector, sized to fit inside the LEGO shell — expect a short play session per charge rather than an all-day handheld. The creator does not publish a runtime figure.

Can I use a different screen?

Only if it matches the exact dimensions in the BOM. The LEGO window opening and the 3D-printed mount are sized for that panel.

Community builds

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Discussion1

FROM THE COMPAREE TEAM

You buy the official LEGO set, add the custom boards, and rebuild the whole thing around them, so it looks like a display piece but actually boots Game Boy games from a microSD card. Would you rather have this or a plain handheld that plays the same games for less?

CompareeTEAM12d agoedited

Practical notes from our verification: the repository has KiCad projects, Gerbers and a pick-and-place file for the main board and the button boards, bills of materials as CSV files, STL files for the printed internal parts, BrickLink Studio models and a PDF with assembly instructions for the top part. The firmware is a separate fork of Retro-Go (greigs/retro-go) with release binaries, so you do not need to compile it yourself. There is no licence file at all, which means the files are public but all rights are reserved, so treat this as a design you can build for yourself, not something you can fork or sell. The creator also sells kits through Tindie, linked from the Hackaday project page, which is the easier path if you do not want to order assembled boards yourself. The two build videos (Part 1 and Part 2) and the creator's Discord are where to look when the rebuild around the electronics gets fiddly. Correction (4 October 2026): we re-checked this page line by line against the project's own repository, documentation and videos, and fixed errors in earlier versions.

Theremin Hero (Greig Stewart)

Theremin Hero (Greig Stewart, Scotland) set out to make the official LEGO Game Boy actually playable, with all the electronics designed from scratch to fit inside the LEGO shell; members of Glasgow Hackerspace helped with the PCB design. He published the board files, firmware fork and build instructions, and offers kits.

GitHub

Star the project on GitHub

DISCLAIMER

  • Comparee is not the author of the projects featured here. All rights to each project belong to its creator — every page links to the original source, and we never host creators’ files.
  • Information is provided without warranty and may become outdated as projects evolve. Prices are indicative bands only — always check the creator’s parts list for current costs.
  • Building and operating any project is at your own responsibility. Protective equipment, safe workshop practice and compliance with local regulations are the builder’s responsibility.
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