The linked page describes it very clearly. The largest fonts on the page say: "8-bit Gaming In Your Wallet" and next to this sentence there is a picture of a credit card sized gaming console.

Just in case you are genuinely curious about the name: it is evocative of the word "arduino", the popular microcontroller based dev-board and "gameboy" the small gaming console.

Why would a hacker care about this? have you ever wanted to fully understand the full stack you are developing for? It's most often hopeless. Even if you work only on open source operating systems, you won't be able to get the documentation of all the chips in your system. Here you can read all the datasheets, and all the code which happens between someone pressing a button and a pixel appearing on the screen. What

I thought the name implied Arduino Gameboy and sure enough that's what it is! Seems like a good intuitive name.

The spellchecker on every new computer I use agrees with you ;)