Titanfall is a first-person shooter from many of the folks who left Call of Duty 4: Modern Warfare developer Infinity Ward. It is a futuristic sci-fi title with warriors in giant, agile robot suits.
Guns that shoot underwater? The sub-surface firefights in Call of Duty: Ghosts might require a huge suspension of disbelief, but the technology itself is very real, and has been since the '70s.