The Outer Worlds

Obviously this can be done on normal, it stacks with the other difficulties so if you choose hard or supernova this achievement pops.

Beating the game requires you to go all the way through Tartarus. Getting the bad ending of skipping the Hope into the sun does not count as "beating the game" for this achievement.

The achievement unlocks when, playing on the difficulty mode of your choice, you reach the game’s point of no return and continue to finish the story. The achievement is story related and unmissable. Your decisions prior to and after reaching the point of no return do not prevent you from popping the achievement.

Additionally, the number of main quests, side quests, faction quests, or tasks you have performed is not relevant to the achievement. The only precondition is that you must advance the story and arrive on Tartarus thus reaching the game’s point of no return. At this point the game gives you the option to create a special save file that can’t be overwritten allowing you to return and mop up as you see fit.

When you reach the Hope, you have the option to skip it to Terra 2 or Tartarus. If you have below average or minimum intelligence and choose the option to skip the ship yourself will result in the Hope flying into the sun. Finishing the story in this manner does not count towards this achievement even though the end credits roll afterwards. The game does not consider this a legitimate end to the story and requires you to load back into the game and safely skip the Hope to Terra 2 or Tartarus.

Skipping the Hope yourself with high intelligence and science or letting ADA do it regardless your intelligence and skills will result in a successful skip to the destination of your choice. Skipping it to Terra 2 puts you on the branch of the Phineas (good) ending. Skipping it to Tartarus puts you on the branch of of the Board (bad) ending. Pursuing either branch to its end, regardless of your choices along the way, will pop the achievement.