The game's artstyle was heavily influenced by atompunk aesthetics, particularly the works of Chris Foss, Chesley Bonestell, and Syd Mead. Additionally, the team researched Soviet designs for spaceships, vehicles, and tools to fit the game's retro-futuristic style.

The Invincible is based on the science fiction novel of the same name by Polish author Stanislaw Lem. The devs chose this novel to adapt because they felt the original novel was "stunningly picturesque", and that "it reads as a ready-made movie script". However, the game is not a direct adaptation of the novel; while the story is largely the same and features several returning characters, the game's main cast (including the main protagonist) are original.