(The story for) Very Cool Gun (VCG): A Rougelike Shooter with Only One Gun

Salient Plot Points

Once Yuko reaches Sheol's core, defeats the boss that resides there, and attempts to destroy the VCG, she finds out that the core isn't strong enough to destroy the VCG. This creates an explosion, killing Yuko and sending her back to Home, the VCG still in her hand. Her fellow crewmates reveal to her that the explosion blew open the core, unlocking two additional areas.

After unlocking the two new areas, Yuko battles her way back down to the core and goes inside. She slowly progresses through these new areas, populated by, amongst other things, the remaining members of Sheol's once thought dead population. Yuko eventually finds her way to the end of area seven, which houses 5-10 pieces of a powerful Elytrum bomb, each piece being so large that she has to take them back one at a time via the Grandfather Glove, necessitating multiple successful runs. Once the bomb is complete, the Red Letters use it on the Out's home planet, which completely cripples their empire and subsequently removes the threat of them misusing the VCG.

After destroying the Out's home planet, a final super-dangerous 8th area opens. At the end of this region is Sheol's true core, a black hole, guarded by the game's true final boss, the mysterious godlike entity known as the "Guardian" that the original inhabitants of Sheol built so many monuments of. Determined to permanently rid the universe of the VCG in order to make it impossible for anyone to potentially abuse it again, Yuko heads back down into Sheol and confronts the Guardian. The chaotic and unstable nature of its arena is too dangerous for Yuko to stay for very long and completely defeat it in a single go, requiring her to whittle it down over multiple runs, similar to the bomb parts. After finally "beating" it (which merely temporarily stuns it), Yuko throws the VCG into the black hole and returns to Home, no VCG in tow.

The Red Letters rejoice as the threat of the Out and the VCG are gone, though their celebration is cut short after learning from the Red Letters that they can't all abandon Home yet as the Red Letters need to securely extract all of the data from Home's servers by manually retrieving them, so as to prevent any remaining Out ships from stealing them and gaining access to valuable Red Letter information, like refugee camp locations or, worst-case scenario, schematics to reverse engineer the Grandfather Glove. So as a result, the crew stays on the base, and in order to pass the time Kalista reconfigures the Grandfather Glove to allow Yuko to slip back into a timeline where the VCG hasn't yet been destroyed, essentially allowing the player to infinitely replay the game even though the main story arc has been resolved.

During this post-game period, if the player has a strong enough relationship built with Kalista or Forrest, they can experience a cutscene where Yuko fulfills whatever promise she made, in Kalista's case visiting her family in Annavarld, while for Forrest the two visit the graves of each others' respective losses.