Ratchet & Clank is a 3D platform-adventure game featuring the protagonists Ratchet, a furry alien creature, and Clank, a small robot. The two travel across the galaxy in search of Captain Qwark and ultimately become involved in an effort to prevent a threat to the galaxy. The game follows conventions established by earlier 3D platform games such as Rayman, Sonic, and Mario while introducing its own mechanics and structure. Its levels consist of large environments with detailed buildings and distant areas that can often be reached and explored. The game also includes several gameplay sequences outside its standard platforming, including space combat and first-person turret sections resembling Missile Command. The game contains more than twenty levels, each set on a different planet, along with numerous real-time cutscenes that develop the story. Progression is partly non-linear, requiring the player to revisit previous planets to complete objectives and offering multiple routes through portions of the game. Ratchet can also acquire or purchase a range of weapons, gadgets, and accessories, each providing different functions in combat, exploration, or puzzle-solving.