Warren Hooley

Easily the hardest FPS game I've ever played. But I really like how it pushes you to become both a great individual player as well as part of a team. This game is for those who enjoy complex challenges and have a drive to overcome it. You need to be ok with failure and use it to learn and evolve. Takes about 200-300 hours to get good enough to beat all the levels, unless you have tons of skill transfer or natural talent.