Fract OSC is presented to the player in the first-person view. As a nameless avatar, the player explores the game's world with little guidance besides visual and audio clues. The game begins on an empty space which, as the player discovers while playing the game, is a giant
music synthesizer, initially defunct. A portal on this level leads to a game's main world space, the insides of this synthesizer. This world is an abstract landscape, comparable to the visuals of
Tron, that includes many large structures along with the unique environmental features. At any time, the player can switch to a special "engagement mode" view that reveals any special virtual controls in the nearby area that can be used to manipulate the game's world. One feature of the world are a number of travel stations, from which the player can rapidly travel to any other previously-opened station. While the player can fall into a lethal liquid at the base of the world, or be crushed by objects in the game world, they are respawned without penalty near a recent checkpoint they passed. The world is divided roughly into three sectors based on colors, red, green, and blue, representing
lead, pad, and bass voices, respectively. In several of the structures are the game's puzzles. The nature of such puzzles are initially abstract but using the engagement mode in proper locations will reveal controls to manipulate these puzzles. There are generally two parts of each puzzle. Within each sector, the first part of these puzzles share a common solution theme, such as manipulating large blocks to specific squares, or routing the flow of sound to a target location. Once this is solved, the player then must set a melody on a smaller synth machine located nearby, as to come up with a rhythm to open up a nearby portal, using visual and audio clues to guess the proper rhythm. Completing both parts of a puzzle unlocks one or more of the larger synthesizer controls in the introductory space, as well as opening up paths in the main world to further explore. Additionally, areas near completed puzzles will emit sound and light effects. Completing all four puzzles within that sector unlocks a larger puzzle for that sector that once solved fully opens up all controls for that synthesizer voice on the main synthesizer. Once all three sectors are completed, the player can complete a final puzzle area that incorporates elements of all previous puzzles to unlock the advanced controls on the main synthesizer and completes the game. At any time, the player can return to the main synthesizer, and using whatever controls they have unlocked, create musical tracks which they can save and share with other users. ==Development==