Geoffery Corin was a Human Starfleet cadet serving the late 23rd century. He was part of a starship bridge simulation cadet group, whose "captain" was Cadet David Forester. (TOS video game: Starfleet Academy)
Geoffrey came from a wealthy family on Alpha Centauri and claimed he enjoyed the best lifestyle and best education. He was up for command candidacy in the Starfleet Academy Command School, but he did not like the responsibility.
During the Command School opening ceremony, Corin took part in a staged terrorist assault with other cadets. He dropped from the auditorium ceiling on a cable and with a phaser rifle he attacked the platform behind Hikaru Sulu and Commandant Aex Rotherot. David Forester dropped on him and pinned his right arm down. Corin pummeled him with his free arm, and whacked his ear. He threw Forester off and took a rifle that fell from Sturek, but Forester plunged for him and landed on his rib cage both slamming into the stage deck. Forester was about to punch him, but James T. Kirk grabbed his elbow; and Forester punched him instead.
Nonetheless, Forester's exemplary courage put him in command of his team and Corin was chosen as a navigator because of his navigation tricks. His first task was to fix the lightning in the simulator bridge rafters. (TOS novel: Starfleet Academy)
Soon after their first mission, Jana Akton clashed with Corin, who claimed semi-jokingly that his rich parents bought him an entrance to the Academy, whereas she sweated for it; during the argument she dropped a mechanism she was holding and rammed Corin, crashing to the Captain's Chair. Forrester had to keep them both in line. (TOS novelization: Starfleet Academy)
Corin was later known to date Faith Gage, the leader of another cadet group. As Robin Brady was intereted in Gage, Akton complained to David Forester about him, noting that his actions affect the other members negatively. (TOS novelization: Starfleet Academy)
After a match with senior cadet Frank Malan's team, Corin supported Malan's speech concerning regulations, and brought up Kirk as an example of how ingenuity and beyond regulations helped him beat the Kobayashi Maru scenario. He also supported Malan saying that hostile action is the only "diplomacy" against aggressive enemies. That day Forester reprimanded Corin about his low scores and how they could bring down the team's average score. Corin promised to concentrate harder and that he'd not fail. (TOS novelization: Starfleet Academy)
Geoffery Corin is loosely based off of the character Geoff Colond, from the console game "Starfleet Academy Starship Bridge Simulator." There are major differences in the characters though; such as personality, responsibilities (helm and first officer for the console-versus navigator and tactical for the PC game), etc.