BioShock vs N.O.V.A. 2
BioShock
BioShock is one of the most highly acclaimed steampunk-themed shooters that has a very interesting twist - your very character's DNA can be modified through the use of a selection of plasmids and a special resource called ADAM, allowing you to have superhuman abilities which will serve you well, sometimes more so than the weapon you wield, in your adventure through the fallen underwater city of Rapture. Aside from the many violent mad men (a.k.a. Splicers), the game also provides players with challeging encounters with the iconic Big Daddies and Little Sisters.When it comes to non-military-styled shooters with an intensely immersive storyline, BioShock is among the handful of the "best of the best" (which includes the Fallout series, the Borderlands series, the Deus Ex series and others). The game boasts of having a rather dark storyline that actually challenges you to think about it in a more in-depth way; to link all the clues together to get the complete narrative that is surprisingly a lot more engaging that you'd expect.
2K Games has just released the remastered version of the very first Bioshock last year and if you can get it on Steam, you really should. The very unique experience it can offer you is very well worth the cost.
N.O.V.A. 2
N.O.V.A. 2 is the exciting sequel to a pretty popular FPS game series. Set in a time 6 years after humanity has successfully repelled the Judger invaders, another more devious, telepathic alien race, the Volterites, arrived under a banner of peace but had brainwashed a majority of the human race into thinking they are some kind of deity who had come to create a Utopian world that humans deserved.Join Kal Wardin once again as he tries to fight to free humans from the corrupting mind control the aliens have imposed on mankind, reunite humanity to rise up against the Volterites and potentially find out what these aliens have in plan for the humans they control.
N.O.V.A. 2 basically retained everything that had made the original game so popular among fans of the FPS genre. Although it's not exactly an innovative sequel, it is still a pretty nice addition to the franchise and well, you get to enjoy a brand-new storyline.
That said, N.O.V.A. 2 is no longer available. If you're interested, you can get N.O.V.A. 3 instead or browse through the list of alternative games below.