Retrovirus

"Retrovirus is a Sci-Fi shooter game that offers both single and multiplayer modes, with a focus on 6-degrees-of-freedom movement and customizable combat. As an antivirus program, players explore and eradicate a threatening virus in a computer system's depths. The single-player campaign immerses players in the game's engrossing plot, while multiplayer allows for cooperative and competitive play with a friend."