A Game Maker Language (GML) developer designs and develops video games using the Game Maker Studio software. They write and debug code in GML, a proprietary programming language designed for this platform. Their tasks involve creating characters, levels, animations, and gameplay mechanics. They also handle game elements like physics, sound, and graphics and may integrate third-party APIs for features like social media sharing or in-app purchases. They test the game for bugs and performance issues, making necessary adjustments for optimal user experience. GML developers often collaborate with graphic artists, sound designers, and other game development professionals.