Encouraging these fans to explore the game is something Super Metroid excels at. Its use of hidden upgrades throughout the game, combined with a percent score at the end of the game to tell players how many upgrades they missed, creates replayability through exploration.
Furthermore, players couldn't see the completion rate until after the end of the game, encouraging them to explore every square inch of the game world before completing it. This intense investigation would lead players to discover that they could "sequence-break," or undermine the critical path of the game, which would encourage even more exploration.
More important than trying to encourage this curiosity, however, is to simply avoid putting up roadblocks. This is actually the one area in which Super Metroid failed. When it was released, it was a closed system, and serious exploration of the game's code was impossible for the average fan.
It was only years later, when the game's cartridge technology itself was circumvented, that intrepid fans were able to explore the code and start the hacking community. Developers don't have to give fans complete freedom with a game's code, but a completely closed system may well cripple a game's community.
By capitalizing on fans' natural curiosity about their favorite game, developers can lead them to a deeper understanding of it, which in turn can give players the knowledge necessary to create new content for the game. For Super Metroid, this ability was key to the inception of the ROM hacking community, but it was only half the story.
Without direct access to Super Metroid's code, major hacks like Super Metroid Phazon Hack, pictured above, would be impossible.
Even if fans have a deep understanding of how a game works, their knowledge may go unused if they have no motivation to do anything with it. By contrast, the members of Metroid Construction used their knowledge to create their own versions of the game, from cosmetic changes to unique spins to complete overhauls.
What motivated them? Forum members said that a lack of a true sequel to Super Metroid spurred fans to hack the game. Simply put, a lack of official content induced a flourishing of unofficial content.
It's important to note, however, that the Metroid franchise did not have to die for Super Metroid to be a unique game. Although there was a significant dry spell of about eight years between Super Metroid and its twin sequels, Metroid Prime and Metroid Fusion, the more important factor is how different these sequels were from the original.
Metroid Prime took the series in a completely new direction, using a 3D graphics engine and a first-person perspective in stark contrast to Super Metroid's 2D graphics and sidescrolling view. And although Metroid Fusion looked similar to Super Metroid, its relatively linear gameplay was seen as a departure from Super Metroid's oft-lauded sense of open exploration. Both these new games thus successfully -- and profitably -- continued the franchise without diminishing Super Metroid's perceived uniqueness, leaving room for fan interpretation.
Although developers strive to make their games unique to stand out from other franchises, this doesn't always happen within a single franchise. Purely iterative sequels can cannibalize extant game communities and suppress the community's desire to create content. If a developer creates new content frequently, it is competing with its own fans' creations -- and the fans usually lose. Fans must be able to see a niche for their content, or they will have little reason to bother. Releasing a sequel every year may guarantee a steady income, but a developer is more likely to curate a self-perpetuating community by helping fans promote and create their own content.
One notable thing lacking from Super Metroid is a strong story element. Ice Metal: Uninstall, above, is one fan's answer to that gap.