The game was obtained by The Lost Levels, a website that specializes in unreleased and prototype video games, from a European collector without any information on what it was. It was to much surprise that the game could be functionally played through from start to finish. The game was made available for play as a ROM for use with an NES emulator. The early, rough prototype of the ROM was also made for release on The Lost Levels, and it indeed had sprites of Superman as the original sprites for the main character, and the background music played in-game replaced with John Williams's Superman Theme. Another unreleased Sunsoft cart in the US can be made to confirm that this was indeed "Superman" originally, as the levels are identical to "Sunman", however they are in a less finished form, and the player is able to skip levels by pausing and pressing the select button.