: You could play as Knuckles in Sonic 3 levels or Tails in Sonic & Knuckles levels.

A cracker or romhacker in the late 90s would use a command-line tool like ipjoin or a hex editor to perform this operation:

SonicKnucklesSonic3Bin remains an enigmatic and fascinating piece of gaming history. Its rarity, unique gameplay, and development insights have cemented its place in the annals of retro gaming lore.

The .bin file flattens that physical miracle into a single stream of 1s and 0s. It is less romantic, but it is durable. Fifteen years from now, when original cartridges have corroded batteries and failing capacitors, that sonicknuckleswsonic3.bin file will still boot on a $5 Raspberry Pi.

Navigate to the folder containing sonicknuckleswsonic3.bin (or its equivalent Steam filename) and select it.