Okay so picture this: all that build-up and the end is just some lame rocket rip-off. You load the cube into the rip-off silo (tasteful, well-done, thought-out rip-off), then some wobbling happens then the fabric of reality tears apart and the cube is destroyed.
And the sequel mods are about like stopping that reality tearing from happening.
Like imagine ghost mode from Interstellar. You're playing somehow on top of your old savegame. Fucking rad!