Leaning against natural selection. I like the description of the RTS part of the game, and people are complimenting it as a good FPS, but it mentions a long time needed to play it at all well, and a lot of coordination needed by teams, and that 'one good players can wipe out whole other teams'. Sounds like a lot of frustration and FPS isn't a favorite anyway.
It takes awhile to get the hang of because they are a good handful of different things to learn. How well your team does really comes down to how good your commander is in many cases. The game is noob friendly though in a lot of ways. They have noob friendly servers that are highlighted different colors so people that play in them expect to play with noobs as well. When you first start playing your name is green to everyone else which lets them know you are new, also asking for help or what to do and the commander will tell you. If you can listen and take simple commands you are fine. A lot of times you are with 1-2 other teammates and you are ordered to defend this area or not go pass xxx.
A good player can obviously clean house like ANY online game and change the tide for his team.
My recommendation for people that first start playing is to play as the Marines only for awhile. They are much more straight forward and easy to understand as they play like a normal FPS. The Aliens are much more difficult to learn the game with and require a high level of skill and understanding due to how they are set up.
When I first started playing, one of my first few games I had a commander that helped out a bunch of the new people by giving us simple commands like hold this area and when other stuff would come up, he would tell us how to do xxx. A lot of people use voice comms in the game so it works out well.