AquaNox

The player once again jumps into the role of Emerald "Deadeye" Flint. After the Bionts are defeated, Flint goes back to being a mercenary as a leader of a Biont-hunting task-force. Things turn for the worse when his submarine, the Succubus, is stolen on one of the stations. The game begins with one of Flint's dubious acquaintances giving him an old, barely-working sub and several missions to get him started. Source: Wikipedia, "Aquanox," available under the CC-BY-SA License.