Atmosphere in games is the hidden layer between the artwork, audio, narrative, and level design, and can elevate the experience above and beyond the moment-to-moment pleasures of the gameplay. What is it exactly, where does it come from, and how can it be implemented and used to good effect? And what do you give up by having it (or not having it)? This talk will answer these questions and more through the story of how our seven-person studio went about creating an atmospheric game on a modest budget in the action RPG, Bastion. In doing so, we will explore a methodical approach to creating atmosphere in games, stemming from a strong sense of tone and theme in a work, the goal of which is to provide a more seamless, meaningful, and internally consistent experience for players.