9. Singularity
In a genre as overpopulated as first-person shooters, it falls to the underdogs to experiment with established formulas, somewhat safe in the knowledge that theyve nothing to lose, and everything to gain. Singularity was one such game, the core conceit being a gun named the TMD (Time Manipulation Device), the implementation of which allowed you to grab and throw objects and soldiers all over the place, alongside phasing in between two core time zones at specific points in the story, contributing to the overall narrative that walked the ever-fluctuating line of believable science-fiction to perfection. Such a narrative was a unique tale of past mistakes effecting the present day, and with your actions being the cause of something that has gone so terribly wrong, the resulting time-zone-twiddling gave rise to a surprisingly memorable story should you take the time to seek it out.