Only later in the game when the commander researches exo-suits with mini-guns do you feel safer moving into alien territory. The feeling of vulnerability while playing a marine is pervasive in the early stages of a game, as you never know when an enemy skulk might drop off the ceiling behind you and start chomping your heels. The aliens can build structures which cloak their infestation and units within a small area, so you might walk into a seemingly empty room only to suddenly find yourself surrounded by horrible alien structures and enemies. Trying to slowly repair the power node while listening to the scuttling of alien skulks nearby is a harrowing and very tense experience. If the aliens manage to take out a power node, an area of the map will become very dark, forcing marines to use their flashlights. The alien skulks have the ability to crawl around in vents, and can be heard doing so as the marines traverse the claustrophobic passages below.

The gunplay in Natural Selection 2 is satisfying and precise, but the combat is not what makes playing as a marine so entertaining. Instead he should follow the orders of the commander, help build structures, and spend resources on upgrades that will allow him to be more effective in combat. A marine who wanders off by himself will quickly be picked apart by the aliens, and will be of no benefit to his team. Apart from commander, playing with the Marines involves familiar shooting mechanics, but much more involved teamwork and order-following than in most shooters.

To help them do this, the marine commander who plays the game like an RTS will direct the foot soldiers on his team to construct a variety of buildings and complete research which will improve the soldiers and grant them access to better weapons. The marines must defend these areas while at the same time attempting to destroy the alien hives and prevent the spread of their slimy infestation.

The marines' job is to restore power to the map by building up power nodes, collect resources by building extractors, and holding these areas by building command stations and support structures. If you feel like shooting things, you will likely side with the marines. From here you must choose which side you wish to play on, a move which will dictate your experience within that game. Upon entering a server in Natural Selection 2 you will be placed into a 'ready room'.

Natural selection 2 dedicated server