FRACT OSC is a first-person adventure game based around three concepts. Firstly it offers the exploration of an abstract world filled with sounds and colour. The player can freely navigate in any direction and needs to solve small environment based puzzles to access all areas. Once discovered, lifts become available to quickly move around sections. There are no threats, but it is possible to fall into the void and then the game restarts at the last lift station.
Secondly it offers more difficult puzzles based around unlocking different parts of a large digital music studio also controlled from the first-person view, the starting location for each game session. The tools are split up into three large synth paths: lead, bass and pad. Each part has its own colour (blue, green and pink) with puzzle sections in the game world that can largely be solved in any order. No hints or instructions are offered, instead the player has to figure out everything through the feedback provided by the visuals and especially sounds. Every path has its own type of puzzles, such as creating synth patterns to move objects or open doors, guiding an energy beam by manipulating the direction and height of platforms, and puzzles similar to the Pipe Dream concept where energy needs to be guides through sets of tubes. There are also other types of puzzles based on platforms to reach the required areas and some require careful observation of clues in other areas. Once a part has been unlocked, it becomes available in the studio. Patterns designed in the game world often build up into the game's soundtrack, completing each other, and keep resonating in the environment. Each part also helps rebuilding the game world, filling it with light and sound. When all three paths have been fully unlocked, a new area becomes available with puzzles based on creating sound patterns as a bridge around blocks.
Thirdly the player can eventually unlock a full digital studio with synths, sequencers and a large amount of modulators to compose custom digital compositions. Each part is unlocked by solving a puzzle. It is a complex environment that allows players to save and share the creations afterwards. Players not interested in the puzzle aspect of the game can choose to unlock the full studio right away.
A large amount of time is spent figuring out the meaning of the game world, its rules and the interaction with objects. It also holds many secrets and optional areas to visit. There are many wide open areas with a vertical design. There are no NPCs or other characters in the game world. Movement is done through keyboard keys or a controller with the mouse to look around and interact with the environment. A second look option needs to be triggered to specifically interact with the environment, for instance for drawing the synth patterns.