The Current Age:
The game is set in the age just before the coming of the New Gamemaster, Alex Williams. Since he hasn't shown up yet, many of the conflicts in the comic are not yet set in motion; everything is set to tip.
Nexus is the hold-out city on the plane where the Palace of Power once stood. Its institutions stand, mostly because what preceded democracy here is a Creators-made monarchy. There are no Creators anymore.
The closest thing to a Creator left is Advance, a strange computer (recall the characterization of Gameboy in the Captain N cartoon), Advance is venerable, wise, and irreplaceable. He has already completed the walls of Nexus, a defensive ring that holds the desert wasteland at bay. He has also already left, for places unknown, or offline. If anything should happen to that wall, the desert would expand through it, taking Nexus at last.
Returning from the desert is extremely unlikely, but has been done. Sprite explorers report that the desert is expanding, that pockets of space remain at its frontiers, but periodically disappear into the sand. Navigating it is considered a near impossible skill check, TN 35 at the minimum once away from the walls of Nexus, as there are no stars, no magnetic north, no points of reference at all. The “ghosts” of the desert are also out there, but they are hostile and incapable of corporeal interaction, except one; they can drain the life from travelers, and certainly talk as though they can take their bodies as their own. Finally, insanely powerful monsters such as Zone Eaters (FFVI) are frequent occurrences, leading to a general sense that travel in the desert is a matter of utter foolhardiness. Access to the desert is only made available by means of gates, the keys of which have already been lost in the desert by explorers unable to return.
The Warp Zones are opening again; thousands of worlds are newly connected, some familiar, some never seen before. All worlds take on general stylings we would associate with the 16 bit age of video games, and players are encouraged to make up backstories tied to wholly new, creatively designed worlds. As such, DMs shouldn't feel any pressure to prevent Sega Genesis or Turbo Graphics 16 worlds from being used. While familiar characters from those consoles are unknown in the Captain SNES comic, it is easy enough to cheat and impossible to enforce a SNES-only scope.
Through the Warp Zones - Backstory
As for travel, Warp Zones aren't totally restricted, perhaps no more so than we restrict airlines. There are nevertheless dangerous creatures beyond the Warp Zones, and exploring new worlds is a job for government agents:
The following draws as much from Stargate SG-1 as from Captain SNES. It is not spoken to in the comic, and can yet be contradicted. For reference, this was written December 7th, 2013, and the comic has dragged on for more than 10 years already.
A Warp Zone command is maintained on the authority of the President of Nexus (before the election and tax cuts of President Haggar). The command is vested in General Pepper (Star Fox SNES version). He recruits, trains, and dispatches teams through recently opened Warp Zones to see what there is beyond. Player Characters are given to designing characters to participate in this program.
While SG-1 can cherry pick the best and brightest service people and scientists of the USA, Nexus is not so lucky. The general political climate is a mess, and is periodically turned upside-down by mutants, refugees, and the occasional High level RPG sprite or boss. It is Nexus Police Department’s job to handle dangerous threats as a police force, and they are ultimately responsible to the average sprite on the street. They can call in the Warp Zone Command to assist, but they will quickly lose the situation, to them!
Service in WZC is hard going. Most citizens in Nexus respect the work done, and those who don’t often learn respect when another lost and confused newcomer washes up in their city. Most citizens, and the Service sprites, also remember being that lost and confused newcomer. As such, WZ teams need quick decision making and are usually trained as both diplomats and soldiers. Any role-playing build can work, as long as it can be justified to the higher ups.
Morale is a perpetual problem, but WZ teams at least knows their duty. Their job is the closest possible to the violence they know from their homes, and they get a stipend of extra lives and can requisition (Charisma check) more as needed. Where NPD frequently finds bringing too much force to encounters can complicate their jobs, WZ teams can bring the thunder, as long as there was no other way. Yeah, there's no way Munchkin players would abuse that set up, is there? ;)
Being equipped is a relative statement. While the PCs can take powers and work to optimize their builds, and NPCs they meet from the duties are surely going to have their own dedicated powers as well. The challenges that they face are totally unknown, and thus they tend to favour being as broadly prepared as possible. Heavy encumbrance is frowned upon, but if you can make it work...
WZC PCs can secure residences in Nexus, which invites interactions with the neighbors (for good or for ill) or take up residence on base. Services (such as gear storage) on base are Spartan, hence there is a trade off.
Sessions begin with a quick briefing, outlining the PCs goals through the Warp Zone, the world encountered and readings that may indicate challenges ahead. The PCs then gear up and go through the Warp, arriving in the new world. From there, the PCs are expected to check back in regularly, and return when the mission is completed, but are otherwise free to explore as needed. Few missions are sent out for pure exploration (mainly because it is more work for the DM than it is value for the PCs).
So that should be enough to start... but not enough to run a memorable game session. I'm at length now, so more will come later.