As io9 discovered, a real website exists for Tuckersoft, the fictional, '80s-era video-game company depicted in the film. In addition to containing background info on the developer's history and most famous titles — like Metl Hed (the name of an episode from Season 4 directed by Bandernsatch's David Slade) — the site also allows visitors to play Colin Ritman's latest game, Nohzdyve (the title of an episode from Season 3). The game involves a character falling from a great height, and it is up to players to collect precious eyeballs on the way down and avoid certain dangers.
If you do decide to download the game (a .tap file) onto your computer, you'll need some kind of emulator to actually play it. i09 recommends the use of Fuse.
Ritman (played by Will Poulter) is the golden coder of Tuckersoft and sort of takes Stefan Butler (Fionn Whitehead) under his LSD-laden wing when the latter gets stuck while adapting Jerome F. Davies' iconic fantasy novel into a game.
Written by Charlie Brooker and directed by David Slade, Bandersnatch is now streaming on Netflix. According to Variety, there are only five possible endings to the movie, but "over a trillion unique permutations of the story."