File Extension SIN File Format SiN game file SIN stands for SiN game file. This was last updated in March 2012 By Margaret Rouse Browse File Extensions Alphabetically: A B C D E F G H I J K L M N O P Q R S T U V W X Y Z # Ask a Question. Find an Answer. Ask your peers a question about this file extension. Ask a Question HTTP *Admin server is not starting crtdevprt How do I make a ball arcing through the air and it's shadow traveling on the ground converge simultaneously on the ground?