Mark Seibert - is a video game composer and producer. Mark Seibert began his career in 1995 and has worked for companies such as Sierra, Sierra On-Line, Activision Blizzard, Assemble Entertainment and Codemasters. Mark Seibert's first game was Phantasmagoria which was released 28 years ago. Best Game Mark Seibert contributed to was Phantasmagoria. Mark Seibert's latest work is Leisure Suit Larry: Love for Sail! which was released 27 years ago.