Metal Gear Rising: Revengeance Walkthrough/R-02: Research Facility

Simply put, not difficult at all, until you reach the mech battle.. because now there are two and the boss hp bar is linked to both of them, simply getting a few hits on one of them is hard enough when the other is spamming machinegun fire and rockets, then comes the infamous cannon combo. being blasted 3 times by its cannon on very hard difficulty will simply lower your entire hp bar to near death, so.. as you can imagine, if they both do it at the same time, thats 2 repairs wasted due to one small slip up. it is possible to avoid the shots that follow after the first, however if you are closer than 20 meters this is not possible as the ministun they give you does not wear off in time to dodge.

not to mention the environment of the battle, the amount of fuel tankers is far greater, and when both mechs start immediately tearing the place to pieces, bits of debree clutter your screen like no tommorow, using ninja run and basic attacking your way around the map until it is clear might seem like a good idea, but you will find it far more difficult as the mobility of the mechs will be far greater than if they are maneuvering around the tankers. the best technique for this battle, i have found, is to have multiple em grenades available, and to throw them at the first mech as soon as the battle starts, the first mech is engaging you but the second is not even aware of your presence. the second mech is at the far back right corner of the room behind tankers and so you should take advantage of this to do heavy damage to the first mech.

if they fire homing rockets, slice them with ninja run to gain additional repairs. there are also repairs scattered in the corners of the map should you need them.