These are the button mappings for an Xbox 360 controller. The emulator is a JavaScript Game Boy emulator. This is loaded on the Chromecast through a simple html file (called the receiver in the repo).

However, Dominic Szablewski has recreated the game in JavaScript for an online competition, producing an executable that is a mere 13KB. The slimmed-down game, called Q1K3, is hosted on JS13K ...