Gregory Callahan - is a video game artist. Gregory Callahan began his career in 2011 and has worked for companies such as Bend Studio and Sony Computer Entertainment. Gregory Callahan's first game was Uncharted: Golden Abyss which was released 12 years ago. Best Game Gregory Callahan contributed to was Uncharted: Golden Abyss. Gregory Callahan's latest work is Uncharted: Golden Abyss which was released 12 years ago.