Game option that turns stars into black holes when you leave a system

[Jimmy]

I used to play the IOS version when it first released. I remember there was an option next to "cemetery gates" that turns star systems into black holes when you leave the system (so you can't go back to refuel, etc.). However in the Steam version I can't find that option. Is that feature removed from the game at some point, or do I need to unlock it somehow?

[Teddykrieger_Michel]

I´d never heared about this option. I think, in the version I´d played, it doesn´t exist. I reached every 5 targets, on stage "easy", and had never seen a button for such an option.

This game with this option would be really HARD.