A Minecraft player has built a working Atari 2600 console within the game’s digital world. But ‘working’ comes with a big caveat.

It’s not the first time somebody has taken advantage of the fact that building blocks in the game can be functional as well as decorative. In 2014 one player created a working one-kilobyte hard drive which used solid and opaque blocks to indicate bits.

Back in July another player built a Game Boy Advance which ran Pokemon, albeit with key functions missing so that it was more of an explorable map than a game.

The latest hardware in the Minecraft world builds on the hard drive, using two thousand dirt and block stones for the bits in the virtual 2600’s memory. The console gets its instructions from “cartridges” for Donkey Kong, Pac Man and Space Invaders.

The big problem is that although the console does actually work, it’s incredibly slow. Rather than a sixtieth of a second, it takes four minutes to draw a single frame. Put another way, the equivalent of a single second of gameplay on a physical 2600 would take four hours in Minecraft.