An American special forces team is sent to investigate a Cold War-era Soviet research installation located on a secluded island. The Soviets, it seems, had been doing research into singularities (a point in spacetime where both density and curvature are infinite and, as such, laws of physics break down, which also explains why there's no way of telling what happened prior to the Big Bang) until something went wrong and left the island barren. As you scout the island, the past forces its way through and makes you change the course of history by doing a good deed to the wrong person at the wrong time.
Singularity has some of the most entertaining firefights in a first person shooter. Your enemies consist of both Soviet troops and former civilian inhabitants of the island who got zombified as a result of bad diet. Most go down with a small amount of bullets and there was something FEAR-like about the game's pacing with groups of enemies at specific intervals. (Still, I'd have preferred more of those long moments when there's no fighting, like the first map.) As an added bonus, you get to chop legs, arms and heads off with well-aimed shots. The game's weapons are fun-looking alternative-timeline variants of modern-day weapons. The weapons can be upgraded at upgrade stations if you have managed to pick up upgrade kits (these can be bought as well but at steep prices). The upgrade system works well, is useful and provides an incentive to look behind every corner in the hope of finding upgrade kits. Abilities can also be upgraded so keep your eyes open for currency. The game also has the best minigun since Quake 2, the worst grenade launcher since ever and a rifle that allows you to guide bullets mid-air. Oh, and the sniper rifle comes with a manual slow-mo ability, guaranteeing dozens of headshots.
Singularity's "catch" is the Time Manupulation Device (TMD) that allows you to bring aged objects back to life, or vice versa, to shoot spheres that slow down the passage of time for anyone inside, and to lift and hold objects (like a gravity gun). The TMD can also be used as a weapon against enemies and its effect depends on the type of the enemy. For example, when used against zombies, their movements slow down to a snail's pace. When used against humans, they turn into zombies, which is useful for turning soldiers against their now-zombified buddies. The TMD is essentially a gimmick but it works quite well, forcing you to do some minor thought work every now and then.
The game has quite an interesting story. Because of time manipulation you never know what to expect. Moreover, forces of history are not beyond your control and, at the end of the game, you have to make a painful choice with no assurance that you're actually making things better: uncertainty bugs you the moment you pull the trigger, no matter who you were pointing at. The maps are visually quite repetitive, mostly worn-down industrial environments that amaze from time to time with Conceptual Grandness and attention to details but it's quite unfortunate that the first map boasts the best visuals. The layout of the island is presented in the first map so you're, more or less, constantly aware of where you're going. An unfortunate little fact is that many of the game's textures are low-resolution, as if the developers never realized this game was going to be played on computers. There are other minor annoyances too such as doors that shut behind you way too quickly, preventing you from backtracking. The game is short, around six hours, which makes it one of the shortest non-CoD first person shooters. The game is also very easy; playing on normal, I died only twice during the entire game despite the fact that the game has a traditional health system.
Conclusion: Singularity has only a few original ideas, being mostly a collection of borrowed ones (it seems that every shooter wants to have a vortex in the sky these days) and not quite having an identity of its own, but these ideas are tied together well, resulting in an interesting, well-paced first person shooter with fun combat, quick puzzles and a somewhat fascinating storyline.