Retro gaming handhelds have had a genuine second life in recent years. Original Nintendo hardware has been cloned, shrunken, and reimagined into increasingly unhinged form factors by modders who see the Game Boy lineup as the most suitable canvas for this kind of project. The builds have become their own subculture, where the unofficial requirement is always constructing something that makes everyone else feel like they aren’t trying hard enough.
YouTube creator Chris Hackmann, known online as LeggoMyFroggo, took things further than most. He spent more than two years building the Time Frog Color, a Game Boy Color shrunk down to wrist-watch dimensions. From the start, he gave himself three non-negotiable rules: it had to use the original GBC CPU, it had to accept physical cartridges, and it had to keep time when turned off. No emulation, no shortcuts.
Designer: Chris Hackmann (LeggoMyFroggo)
Those three constraints drove everything that followed. Standard GBC screens are too large, so the display was scaled down to a 1.12-inch LCD. That screen can’t read the GBC’s parallel RGB output natively, so an RP2040 microcontroller was added purely as a signal translator. This created the foundation for a stacked PCB arrangement, with an LCD driver board on the bottom and the CPU board sitting just above it.
The cartridge requirement was its own puzzle. Standard Game Boy cartridge slots aren’t watch-sized, so Hackmann swapped the slot for an M.2 connector, the type normally found in NVMe computer drives. The custom cartridges that plug into it aren’t simple ROM cards; they’re full MBC3 flash builds with their own RAM, mapper chip, and a coin cell battery that keeps save files intact between sessions.
All of that stacking pushed the watch body to 15mm thick, noticeably chunkier than an Apple Watch at roughly 10 mm. There was no room for a battery inside, so it went into the silicone strap instead. A flexible PCB runs through nearly the entire band via overmolding, carrying power back into the main body. It’s a bizarre solution that also happens to be the only sensible one.
The watch body is CNC’d from 6061 aluminum and anodized purple, which reads as a direct nod to Nintendo’s color sensibilities. Controls are fitted into the sides of the housing, with four face buttons on one edge and a custom-machined rocker D-pad on the other, both backed by silicone membranes. The unit shown in the video doesn’t include a speaker, as the component missed the deadline.
Hackmann is upfront about the trade-offs. The Time Frog Color offers a “less than optimal playing experience” by his own admission, with battery life that won’t compare favorably against most wearables. It’s a thick, quirky device with controls tucked into the edges and a cartridge protruding from the back. But you can load up Pokémon Gold and play it on your wrist, which isn’t something most projects can claim.