It used to be Factorio for me (I live in Australia, so long flights happen a lot). The problem with Factorio the flight isn't long enough! and the game bleeds into 100+ hours post-flight.
Dwarf Fortress. That's really how to suddenly say "Oh, how did it get to 4am already?"
Dwarf Fortress. That's really how to suddenly say "Oh, how did it get to 4am already?"