You're still building your factory on Satisfactory's planet, but now StarRupture's star erupts on a cycle.
How it plays
A countdown at the top of the screen tells you when the next rupture hits. When the warning starts, StarRupture's base alarms sound and its heat-wave rumble starts to build.
Then the firestorm sweeps over. The screen glows red, and any pioneer without a roof overhead burns until they find cover. Ten seconds in the open hurts a lot; staying out for the whole storm kills you.
Afterwards the star calms down, StarRupture's regrowth music plays, and the clock starts counting toward the next rupture. Between storms, StarRupture's building music plays.
A full cycle takes about 10 minutes, so build your shelters early.
StarRupture really is in it. The music, alarms, heat-wave ambience and burn sounds come straight from your own copy of StarRupture. Rupture Cycle reads them from your install every time it runs, and nothing from StarRupture is shipped. Both games need to be installed.
Solo. Works alongside a normal Satisfactory save. Your factories aren't damaged; only the pioneer gets burned.