Grossman joined Lucasfilm Games, later known as LucasArts in 1989. At
LucasArts, Grossman wrote and programmed
The Secret of Monkey Island and ''
Monkey Island 2: LeChuck's Revenge together with Ron Gilbert and Tim Schafer. He later co-designed Day of the Tentacle''. Grossman quit LucasArts in 1994 to begin a freelance career. For
Humongous Entertainment, a company co-founded by Ron Gilbert, Later he also wrote children's games for Hulabee Entertainment and Disney. He then designed adventure games at
Telltale Games, a company founded by LucasArts veterans. He joined Telltale in 2005 as lead designer. on Telltale Games' episodic
Tales of Monkey Island. Reactive Studios has since changed its name to EarPlay. In 2020 he joined
Ron Gilbert in developing
Return to Monkey Island. The game was released in 2022. ==Children's books==