Anyone not familiar with the Metal Gear video-games should probably go through the various tutorials. In fact, even those who know about Metal Gear should do it. This is a whole new direction for the franchise and so there is a lot to learn about.
One of the key differences is the fact that Raiden’s adventure focuses primarily on physical combat. Raiden is still able to equip secondary weapons such as rocket launchers; however, the use of blades like his trusty katana is the main way to fight enemies.