Gameplay in Size Matters is fast-paced and action-packed, with a mix of exploration, platforming, and combat. Players control Ratchet as he navigates through various planets, fighting against Drek's minions and solving puzzles to uncover the secrets behind Chairman Drek's plan. The game features a variety of gadgets and tools that Ratchet can use to overcome obstacles and defeat enemies.
The gameplay is divided into different levels, each with its unique challenges and objectives. Players must use their skills and wits to progress through the game, and the overall experience is both thrilling and humorous.