Natural Selection is described as '2 is a RTS/Shooter/Biter that you either play as marines or aliens, it is currently under development by Unknown Worlds' and is a first-person shooter in the games category. There are more than 10 games similar to Natural Selection for a variety of platforms, including Windows, Mac, Linux, Xbox and Playstation apps. The best Natural Selection alternative is Doom. It's not free, so if you're looking for a free alternative, you could try Tremulous or Unvanquished. Other Natural Selection like games are Prodeus, Shadow Warrior (Reboot), Dead Space and Aliens vs Predator.
Doom is a science fiction horror-themed first-person shooter video game in which players assume the role of a space marine, popularly known as "Doomguy", who must fight his way through the hordes of invading demons from Hell.
Prodeus is a first-person shooter of old, re-imagined using modern rendering techniques and technology. Experience the quality you’d expect from a modern AAA game, designed with retro aesthetics and gameplay that invoke the tech-imposed limits of older hardware.
Shadow Warrior is a series of first-person shooter video games that focuses on the exploits of Lo Wang, a modern ninja warrior who fights through hordes of demons.
Tremulous is a free, open source game that blends a team based FPS with elements of an RTS. Players can choose from 2 unique races, aliens and humans. Players on both teams are able to build working structures in-game like an RTS.
Unvanquished is a free, open-source first-person shooter combining real-time strategy elements with a futuristic, sci-fi setting. It is available for Windows, Linux, and Mac OS X.
Dead Space is a survival horror third-person shooter video game for Microsoft Windows, PlayStation 3 and Xbox 360.
Dead Space is knows for Its Single player campagne while NS2 is Multiplayer Only. NS2 Has RTS elements that makes it unique among the FPS games currently available
Aliens vs. Predator is a science fiction first-person shooter video game, developed by Rebellion Developments
Aliens vs Preditor has no RTS elements like the Commander and Base Building in NS2
Zandronum is a multiplayer oriented port, based off Skulltag, for Doom and Doom II by id Software.
Battle through an onslaught of mystical backwater cultists, possessed militants & even darker forces as you attempt to discover just what lurks beneath the Earth in this retro FPS inspired by the '90s legends.
Wrack: Exoverse is the follow-up to the 2014 first-person shooter Wrack. It was a very fast-paced, arcade-style game with heavy influences from classic shooters like Doom and Quake.
United States
Canada
Poland
EU
Japan
The Core Element that makes Natural Selection 2 Unique is the RTS part that is not existing in Doom. Also Doom is a more known for its sigle player experience while NS2 is Multiplayer only