METAL WOLF CHAOS XD

Not really that hard at all if you've upgraded everything to the max, you can blast through most levels fairly easily. Only the final boss is somewhat of a challenge as it can take quite a bit of punishment and can kill you quick if you aren't careful, i'd recommend trying to keep your distance by taking cover behind the pillars instead of trying to fight him on the ground(which is incredibly risky as it feels like it comes down to dumb luck whether you get hit or hit if you try and avoid his attacks by strafing) and using a sniper rifle on him when peaking out of cover for the first phase as his attacks can't reach you behind cover all the way up there.

For phase 2 use your burst unit as it will do a lot of damage and let you shoot down all the missiles coming your way, then for phase 3 use whatever sniper ammo you have left to quickly kill the boss before time runs out.