Mouse P.I. For Hire is a monochrome first-person shooter that features Jack Pepper, a mouse detective, who navigates a gritty world while solving a mystery involving missing damsels and shrew plots. The game draws inspiration from classic FPS titles like Doom and Half-Life, offering straightforward gameplay with a rich environment. Players return to a hub area to interact with locals and gather clues. The game includes various missions that involve navigation, clue discovery, and boss confrontations, set in diverse locations such as a harbor and haunted village. The visual style employs rubber hose animation, and the voice acting by Troy Baker adds depth to the character. The shooting mechanics are adequate, with some weapons feeling less impactful than others. The game is recommended for fans of vintage cartoons, classic shooters, and cheese puns.