Game Introduction: SA is a study of extraterrestrial biology biotechnology companies, they privately plan to do some evil, and now you must go to SAC2 base and investigate the theft of antibody ~ Dick, your code is 21, Emma, the code you are ... 12 back on the second follow-up story, to continue in-depth ... the first person 3D shooting game Double cooperation, very cool, very fun ~ Play: Players 1, mouse shooting, player 2, Enter . II In addition to shooting, but also rich in many a number of puzzle elements. (Note: Game has 6M, load please be patient, get stuck, please refresh or change lines)